Welcome to FT!
You can't consolidate miles between different FF programs without massive devaluations (and often not even that). If the DL/NW merger goes ahead your miles in both programs will be likely combined, but that may be too late for you.
Some basic questions:
Would you like to redeem awards, or buy economy and upgrade, or may be a combination of both? How many miles do you have? How flexible are you with dates? Do you have status with any airlines?