I think that when I initially installed Kdenline I selected the wrong "project setting" I selected HD 720P 60 fps and know that need to change that but I'm not sure what to change it to? I just tried to render a simple 3 minute video and the final file size ended up being 875MB. I'm trying to make videos that are 5 minutes and no larger than 100MB n size. There are several other options and I guess I really don't understand why this setting is so important and how it affects the final outcome of my video since it also asks for options when it's time to render it. I would prefer .avi or MP4 if possible? I guess I'm a little confused as to exactly how the process works? Any suggestions?

It is like setting the page size in a word processor. You can change it, but I do not suggest to change the frame rate as that will mess up your edits. Unfortunately, you are using 60 fps, which is way higher than most people need and if you are targeting a smaller output.