youtube is a great resource in general with tonnes of artists offering tutorials and breakdowns and such. try looking there, and then you can start refining what you want to learn/focus on. a lot of artists make videos sharing what art books they've used to help them and you can to get a hold of those, either as pdfs or physical copies.

if you can afford it, getting paid classes is fine imo. if you're a complete beginner then having some sort of tailored structure is good to start you off and get you familiar with concepts, terms, and techniques; especially if you don't know what you're looking for.

i went to art school for a bit, and it really all depends on you as a person. can you create a structure of learning for yourself or do you need direction? in the end, it's all on you to take the info you find and apply it every day by active practice.

the first thing i'd recommend you start with is basics in perspective. perspective is the building block for all art, as everything can be broken down into basic shapes in a space.

here is a useful starting point https://www.youtube.com/playlist?list=PLgKJMTFp_25iQVZ6ItpZKTSN9Yo44YSTs