I have Ashampoo.. I can't convert the files right or something?

I have ashampoo.. the dvd burning software. I cannot get the avi files to mpeg right or something.. And I have 120 min dvds, and I can't burn a 90 min movie on to them? Does anybody have any advice.. Or a freeware that I can convert avi to mpeg without any major watermark (watermark okay, as long as its not horrible)? Any advice would help.. Even if you would like to advise a different dvd burning software - Free. I mean seriously.. 10 years ago I paid 25 dollars for a dang vhs, I just want to switch them to dvd without paying a million dollars.