So hey can anyone suggest me in which frets I can play when playing over Dm and Em? I honestly don't know much of anything about keys, and I'm just starting to learn the notes on the guitar, so all I know now is that I've written a song using those two chords, sad stuff obviously... So any tips on finding which scales go with which chords?

Thanks a lot!!!
For that progression, D dorian would work well. The notes in that scale are D E F G A B C, which you can play anywhere you like.