I play this with my GF who knows DnD, but other than that I basically went into this knowing nothing about the rules.
It feels a bit overwhelming at first, but the basics are pretty simple in the end. This is pretty much the kind of game where you don't need to create the most optimal "build" to do something.
Here's my quick tutorial from a noob to other noobs:
- Pretty much everything is a roll of some kind of dice. 1d6 means 1x six sided dice (so you get 1-6). 2d8 means 2x 8 sided dice (you get 2-16).
- In dialogs you can often say something and it does a check to see does it succeed. E.g. you can lie (Deception), you roll a 1d20 and you need to get at least e.g. 10. You can be proficient in Deception so you get bonuses to your roll. Your Charisma also gives bonuses to Deception rolls and to many other. You can be the best liar and still fail. Or you can be the worst liar and still succeed.
- You can also some times get Advantage to your rolls meaning you throw 1d20 two times and use the better roll as your result. You can have Advantage on attacks too and it rolls the approriate dice for that. Disadvantage is the other way around. Two rolls, use the worse one.
- Combat is turn-based. You can move, do an action (usually one per turn) and one bonus action (usually also one). Any order. Attacks are usually "actions", utilities are usually bonus actions.
- If you are a spell caster you have spell slots. Spell castings are actions or bonus actions, bur they also consume spell points. Cantrips are spells that do not consume spell slots. Level 1 spells consume level 1 spell slots. Level 2 spells consume level 2 spell slots and so on.
- After fights you usually need to rest. You can do two short rests to regain some hit points. In the end, you need to do a long rest which will replenish your spell slots and all hit points.
- There are bunch of class specific things like Warlock spell slots that replenish on short rests or Fighter's superiority dice that are used for more powerful attacks or abilities.
These are the very basics that came into my mind. Some additonal advice would be: don't try to min max your character and just have some wholesome fun!
Jesus saves.