Here are links to some really great online resources to help learn or practice musical concepts.
Musictheory.net has a vast collection of lessons and exercises for all levels of musicians. It's a great resource for practing note names, but you can delve into almost any music topic of interest/that you need some extra help understanding.
Music Racer is an online game where you can practice both note names and instrument-specific fingerings. There are different levels of difficulty all the exercises are tailored to individual instruments.