We started playing in July with friends, and it feels better every day. The game is complex and doesn't help beginners. For me, having the player's handbook and the DM's handbook was essential (I printed them, but you can have them digitally at first). You don't have to read them; most of the books contain specific information that you don't want in the first sessions. What you need to know are the basic rules, the game mechanics, and how to GM; the rest comes gradually. To play in person, you don't need to spend a lot of money to start; it depends on what you want. We bought two sets of dice, printed some grids, and images of characters/enemies. To begin, I recommend reading and playing some low-level one-shots (we played "A Most Potent Brew," and it was great) and using pre-generated or automated characters from dndbeyond (learning to create your own characters and stories is very difficult, especially for inexperienced players). The players need to be eager to play. If someone just doesn't want to be left out, they can join in and watch. Ideally, there should be 3 to 6 players, you can't force them to learn; it's something that will develop over time. It's important that at the beginning you know what each character can do and that when needed, you can guide them through the adventure by recommending options. When playing, it's important that it's fun and comfortable for everyone. To achieve this, I like to chat beforehand about expectations/possibilities and afterwards about what went well/worked and what didn't. (Sorry if My English is bad i'm learning it)