#1
How do i figure out what modes to play with each other?

Also do the mode shapes change for each key?
#2
no, shapes stay the same. just get moved up and down the board. Minor modes can normally be interchanged with other minor modes (e.g. fade to black uses Aeolian and Phrygian) and major can be can be changed with major. Basically, just look at the key of the song.