I have a vid i really like.It's with sound and all.But i don't know how to make a beatmap out of it either which file it has to be so osu can accept it. .____. Help. .___.
You can separate a video file into the audio and video by using a video demuxing tool such as Super or VirtualDub. There are plenty of tutorials already available for these types of software, so just look into them or try out the software for yourself.
Reminder: Video files in beatmaps are not allowed to have audio in them, they must be separate. (I think that is the going rule anyway)
As I stated before the best thing to do if you are lost is to look up online tutorials because they can probably explain it a lot better than I can. I would suggest looking for words like export audio or re-encode. those will probably lead to the results you are looking for.
If those searches yield no results, then I guess I can try to help you. First tell me what video format is your video currently in so I can tell you what program to use exactly.