I just completed my freshman year and I am getting ready to train for cross country (once my coach mails the summer training logs) this was my first year doing cross country and I went into the season without doing anything over the summer because u was planning on doing volleyball instead (I didn't make the team so that's why I did xc) so my PR was 24:26 and that was at regionals at the end of the season! Is there any way that with summer training I could improve a lot on this time? And what work outs can I do that will help me improve the most! My goal is to get 23:30! Is that realistic?
Do the summer workout plan your coach sends. That's what it is for.
If you haven't gotten your soon, you might consider contacting the coach and asking if they have been sent. If they have, that means your was lost and he/she can send you a new one. If they haven't, it will serve as a gentle reminder to the coach to get going and mail them.