Great gift ideas for your gf, 1 month together, want to make it my self and we're both in high school?

a chocolate bouquet!

something like this:
http://www.wikihow.com/Make-a-Chocolate-Bouquet

You can add in real flowers to the bouquet to make it look big and grand.

Gift her a alarm clock.

Well, you could just bring her some flowers. Maybe you could make or buy a card for her. You could take her out for dinner too. Also you can bring her chocolate, those thing are cool.