You have plenty online and offline free resources to train your ears, and recapitulate your knowledge of theory.
I use daily site called teoria. It offers some articles about theory, and also it has a lot of exercise. Namely, you can train your ear in recognizing triads and seventh chords, intervals, scales, rhythm, melodic dictation etc.
I suggest you start with simple intervals and build up from there. When it comes to practising chords, a good knowledge of triads is required (namely, you need to recognize the difference between major/minor/diminished and augmented chords, and later when you develop your ear, whether the chord is in the root position or in one of its inversions).
If you want to practice rhythm, and sight reading a good place to start is Lenmus Phonascus software (it works on Windows, and some versions of Linux). You have both theory and a lot of exercise in this program. I suggest you use it for rhythm training and sight reading. Every exercise is accompanied with short introduction. My advice is to take it slow, let exercise sink in with you even it they seem to ease at first.
It is very important to practice daily. But you don't have to spend your whole day practising. Usually for me, around 15 minutes of teoria.com and about 10 minutes of Lenmus a day are enough. Though, if you can't recognize intervals now, it could take you a couple of months to learn.
For theory, consider reading a book on theory along with course you are watching. A good book can go much more into detail then a course. A good online course will provide you with a solid foundation.
One more good site to consider is musictheory.net.
Disclaimer: I'm not associated with any of mentioned software solutions.