i have heard that every mode has its own feeling or mood to it. i can't seem to figure out what each specific modes feeling is when i play through it. also can somebody explain how to choose a mode or scale for jamming along with a song that will sound good. most of the time when i try to jam along the scale i choose just doesn't sound right. Thanks for the help!
They go from progressively light to progressively dark as you flat each note, in this order:
Try them all over the same root and you'll see what I mean.
Picking the right scale for a tune is a lifelong process to learn. In general if it sounds majorish try Myxolidian, if minorish try Dorian. There will be exceptions but those are the two most important and will cover most of the GD.