Best settings?

So I'm fairly new to Fcpx and I can't quite figure out the best render settings. I've tried to look on youtube, google, and other sites to get some insight but no matter what I do the quality just seems crappy. I realize that it could be the footage that I'm editing with but this happens with EVERYTHING I edit with.

My current settings are 720/1280 30 frame rate 48hz apple prores 422 with stereo audio what am I doing wrong? I've even tried rendering in h264 format and yet it still looks crappy

What are the complete and exact specs of the original media? Don't use 30fps.

I'll try to be precise its 720x400 23.98 fps NTSC 1080p with stereo audio the codecs are AAC, H264 48 HZ

This makes no sense. 720x400 is sub-standard definition. You have to export as standard definition. You can't miraculously make it HD. Do not change the frame rate. Do not use compressed audio in video files in FCP. Only use uncompressed 48k.

Thanks as stated I am fairly new to it so I didn't realize my error

Here's the thing.

1- Know the native codec, frame rate, frame size of all your clips before working with them.

2- Any time you enlarge a clip to fit a larger frame size, you will lose some image quality. The more you scale it up, the worse it gets.

3- With mixed resolution clips, the best resolution you'll get from the finished project is the resolution of the smallest, slowest, lease resolution clip in the Timeline. The weakest link.

Hope that helps.