Best software for homemade YouTube videos
A great choice that works on both Mac and PC is DaVinci Resolve.  The Lite version is free, and if you use only the basic features, it is very intuitive and easy to learn, from drag-and-drop media to basic editing to automatic delivery to YouTube.

A second recommendation is this: software is great for controlling edits, meaning cuts, transitions, wipes, dissolves, and generally assembling footage so that a sequence of shots tells a story, possibly syncrhonized to music, sound effects, or whatever.  However, a great edit will get you only so far when your footage is sub-standard.  Don't waste your time looking for software to fix sub-standard footage.  Learn about lighting (especially 3-point lighting), camera movement, and camera support.  If you don't like your audio, don't waste your time looking for software to clean it up.  Learn to record audio properly, with microphones positioned appropriately.

It may well be that you are very happy with the audio and video you are capturing, and that editing really is the only thing you need to worry about.  Good for you!  But if you are trying to get better looking video or better sounding audio, fix it at the source--with lighting and proper mic techniques.  It takes years of practice and the very best to work magic with software to fix what should have been done right in the first place.

Once you have learned lighting and audio, then you can really go nuts with Resolve, making good footage look great.