From the Pokemon Centre entrance, go to the side of the road directly opposite. Near the corner, there's another of those red gates that you can use. Head south through the patches of tall grass to pick up the Revive next to the palm tree, which you may have seen earlier.
Back on the main street, continue following the main road past the Pokemon Centre. As you approach the T-junction, you'll overhear something about Team Skull near the marina. Hmm, sounds like bad news. Turn left at the junction and follow the road south. If you turn right, you'll find Hala blocking the road.
While you do so, keep an eye to the left. Just before you turn the corner, there's a gap in the hedge. Head on through to discover a veritable mansion. Whoa. Before entering, go up to find a swimming pool. Yikes, who's the rich guy who lives here? While you wonder, grab the Ether sitting in the far corner.
To satisfy your curiosity, head on inside the mansion. Casually make your way to the kitchen in the top-right corner to receive a Lumiose Galette from the Kalos region. That's all for items, but you're welcome to peek around the rest of the mansion, including upstairs.
From the corner mansion, carry on following the main road as it turns and stretches east. Not long after passing the corner, there's a large building to the north. Go inside to discover its the town hall. Or perhaps you're already familiar with it from the Sun and Moon Special Demo.
In any case, chat to the lady sitting on the waiting bunch just ahead for a free Revive. That's two in one day! After you're finished your business, return outside and continue east. As you approach the malasada shop, Hau will come out to say "hi". Once you regain control, head directly north for a moment.
There will be two red gates, the north-most one the same unusable one from earlier. Instead, swing open the red gate to the left. On the other side, wade through the tall grass to retrieve the Tiny Mushroom on the floor. If you want, you can sell this later, at a Poke Mart, etc.
Next, return to where Hau is. If you've got time, you may want to visit the malasada shop to his right. Here, you can order Sweet Malasada for your Pokemon to eat or Big Malasada to take out. If you feed a Malasada to a Pokemon that likes the flavour, you can boost its Happiness stat.
Pokemon will like Sweet Malasada if their Nature increases their Speed stat. In other words, Timid, Hasty, Jolly or Naive.
To the right of the malasada shop is a conspicuous empty lot currently occupied by Machamp. The empty lot is, well, empty so don't expect much. Directly opposite of the empty lot, however, is another fenced off area accessible via a red gate. Head east through the grass to recover TM49 Echoed Voice.
Back on the main road, there's one more building to visit if you want: the police station. There's sadly nothing inside, but what can you do. To finish off your tour, go past the police station and follow the road south after the corner. As you reach the steps, you'll transition into the Marina.
This is where you'll find the ferries used to travel between the islands. Right now, head for the very centre of the Marina to find Captain Ilima just standing around. If you speak to him, it will trigger the next event. Before that, you may want to finish the rest of your sightseeing.
Head left from Ilima to find a pair of tourists in heated discussion. Speak to the male to receive an X Attack and the female to receive an X Defence. These items can be used in battle to temporarily boost your Pokemon's stats. They're better here since they boost stats by two stages and not just one.
To the pair's right is the ferry terminal, but there's not much of interest right now. Finally, make your way to the east side of the Marina and go down the slope to the lower area. Keep going to find a Super Potion near the far end, below the man and his Corsola. Okay, now you should talk to Ilima.
A pair of Team Skull Grunts will appear to harass you. With Ilima's help, it shouldn't be too difficult to stop them. When you're ready, talk to the Grunt in front of you to immediately begin the battle.
Team Skull Grunt
This common bat is fodder for Popplio or Litten or most Pokemon in fact. Avoid using Rowlet since it has a severe type disadvantage. Pichu or Magnemite are good at taking it down.
After sending the fools running, Ilima will heal your Pokemon and challenge you to a Pokemon. If you're not feeling confident, you can back down and ready your party in your own time. Otherwise, hit him with everything you've got!
Yungoos isn't particularly threatening, but Ilima is still a captain, so don't take him lightly. Use Potions if you have to, especially since Ilima may use them himself. For an easy win, have your starter Pokemon lead the charge. Or Magnemite if you have one and prefer to play defensively.
Smeargle is tricky because it will have a move that's super-effective against your starter Pokemon (Water Gun against Litten, Ember against Rowlet or Leafage against Popplio). To combat it, you should send out a Pokemon that resists (or is at least neutral to) the Type that your starter is weak against.
If in doubt, refer to the Type Match-Up chart near the start of our guide. Alternatively, since Smeargle doesn't gain STAB with those moves, you can brute force with your starter Pokemon, but only if they're high level and they haven't taken serious damage from Yungoos.
Emerge victorious and Ilima will recognise your talents, formally inviting you to challenge his trial at the Verdant Cavern. As Ilima mentioned, you can get there via Route 2. Start by making your way back to the Hau'oli City Pokemon Centre.
By the way, all the red gates that you couldn't use before are now all accessible, so you can use them as shortcuts if you want. Most notably, you can use the north-facing red gate to the left of the malasada shop to potentially shave seconds off your journey time.
When you reach the Pokemon Centre, it might be a good idea to heal up your party and stock up on supplies. You've got another route up ahead, not to mention an island trial, so a bunch of potions and poke balls wouldn't be amiss.
Once you're ready to proceed, turn right at the T-junction to catch up with Lillie. Then continue following the road north, towards Hala and the Tauros from earlier. Give Tauros another friendly pat and you'll be good to go. Onwards to Route 2!