You always edit in the rawest format that you can get from your equipment. The D5300 put's out a MOV @ 1920x1080@60FPS.
If your computer can't pull that video file in and edit it, get a faster computer, they are like $499 at best buy
I'd suggest trying Adobe Premier, you can get just PP for like $21/month, or the entire suite of programs for $40/month. Black Friday special till Nov 30th.
Like bronco67 stated, never use a compressed format to edit in, the results will suck a sweaty ball sack
