I race in 5ks for HS cross country, and my PR last year was 19:30. I want my time this year to be around 18:30 so i trained harder than usual during the off season to build a good base and put in a decent amount of miles but i have barely improved from where i was at this point last year. Im running 7 days a week right now and was wondering if maybe that frequency of running might be hurting my performance. Should do a mix of easy, long, and hard days for 6 days and then on the seventh only do like 2 miles? Or should i do something else to improve like lifting weights with my legs and continue doing a decent amount of miles every day?
You don't say what you're doing now so It's pretty hard to tell you what to do to improve. And I'm not a coach so my advice would be limited. One thing I would recommend is to be like that fellow in the Bible and on the 7th day, rest. The other thing you might want to do is find a coach. Check into local running clubs or running stores to see if you can find someone local who is willing to coach you. (One would assume your cross-country team has a coach but you would have to decide if he would be a good coach year round.)
If you're running 6 days and one lighter day, you're not giving yourself enough time to recover. Try taking a day off after a hard day to let your legs recover and rebuild stronger. Continuing to hammer your legs day after day doesn't give your body a chance to recover and get stronger.
Also look into fartleks. Here's an active.com article on it: