Music Theory.net is a helpful website where students can study basic music theory concepts such as clef notes, note durations, time signatures, and much more. The website breaks down this information into short lessons that the student can devote time to each day. Exercises on this site are also helpful in supporting content knowledge learned in class, as well as informing of concepts students may not experience in class!
Teoria.com is a more experience-based website that challenges the student to complete short tasks within a given time limit! This site has many music theory and ear training activities that will aid well in developing the budding musician.