This is my first time editing a video on my computer. The videos I worked with where in MPEG-4 and I just finished my project. The big problem is that nothing happens when I press Start in produce. I want the finished product to be in high def MKV or H.264 but none of them works. I have no clue why

Also another problem the videos I imported are filmed in 30 fps but even when i changed the settings to 30fps (NTSC) in the program i get a warning where it says my settings are 29.97 fps..
I hope someone can help me..I loved working with the program, but sadly, I lose all motivation when I'am so close and yet cant finish my project like I intended.