Hello

D&d can confuse you at the start, there is a large amount of rules and a lot of books. I am going to tell you what books are the most important and what the other books are and other things you should buy when starting out. Note: the books I am going to talk about are quite pricey and you only really need the players handbook to get started.

Core books

The first thing all players should buy is the players handbook, this shows you how to create a character, about spells and how to play the game. The next book you should purchase is the monster manual, it shows you the monster of D&D, their stats and weather their good or evil. If you and your friends are all starting out you also will need the rulebook. Next you should get the dungeon masters guide, it shows you how to make good quests, and contains all the info needed to run a game of D&d if you are planning on becoming a dungeon master.

The 2 core books I have

Adventure books and sourcebooks

If you already play D&d and want more stuff to adventure with their are more than 30 adventure books and sourcebooks to choose from. They include: Fizban’s Treasury of Dragons, Storm King’s thunder and more. These books are great for if you want more adventures or more things to create quests with.

Other stuff  that you can get and some last essentials

Dice are some of the most important thing in D&D, you cant play with out them (the dice decides almost everything that happens in a game of D&D. Some people also have screens, miniatures, cards with important info, maps, grids, and other items that can be useful.

I hope you find the info useful

Heres a link to D&D beyond (used to play D&D online). https://www.dndbeyond.com/

May the rolls be in your favour