My biggest mistake at the beginning of my poker journey was that I spent hundreds to different courses, softwares etc, but the only way to learn is by doing, play as much as possible, make as many mistakes as possible in the beginning and learn by them. Don't try to follow slavishly some strategy. Learn just some basics like hand charts etc and create your own playing style, that's the key of the poker. Poker is profitable when people play differently than others, if everybody is following the same strategy, nobody wins, except the poker room.
Sign up to advancedpokertraining and pokerstrategy.com, basic versions are free, all you need as the beginner, later you can buy premium membership with your poker earnings.