At first, you will give up on more problems than you will solve but don’t get discouraged and learn whatever is taught in the editorial. Just google anything ( even a single word ) that you don’t understand in the editorials.
Don’t give up on problems too easily though. I would suggest you take part in Long Challenges here on codechef. That way, you get a lot of time to think. You can spend a week on a single problem if you have to. Look at all the problems and don’t give up trying to solve a problem at all in Long challenges.
For a collection of well known/beginner problems, you can try a2oj.com ladders.
Last advice I can give you is find someone who is interested in competitive programming too. Your profile says you are home schooled so you can find someone in your neighbourhood. This will help you tremendously.