All of the Borderlands games have had it where you only started with limited weapon slots upon beginning the game. As you played through the main story, you would eventually unlock the other weapon slots, allowing you to use more weapons during battles. This page will detail when you unlock the third and fourth weapon slots in Tiny Tina’s Wonderlands.
How to Unlock the Third Weapon Slot
When you begin the game, you will only have two weapon slots available to switch between during battles. You will unlock the other slots by going through the main story missions, with the third slot unlocking upon completing Thy Bard, With a Vengeance. This is the fourth story mission in the game and entails you with finding a bard to bless your voyage across the waters, culminating with a boss fight against the Banshee. The third weapon slot will be one of your rewards to finish the mission.
How to Unlock the Fourth Weapon Slot
The fourth weapon slot will require you to get a little farther than the previous mission outlined above. After completing Thy Bard, With a Vengeance, you will have a shorter main story mission called Emotion of the Oceans. Following that story mission will be the sixth one in the game, called Ballad of Bones. You will begin your journey to the Fearamid with this mission and one of your rewards for finishing it will be the fourth weapon slot being unlocked. You will now be able to equip four weapons to use in your Bunkers & Badasses adventures!