@Wildcard: Please don’t take offense but it seems as if you need to do some basic learning about the medium you’re trying to work in. It’s just too complex a subject to put it all down in a forum post, and even then, the explanation probably would assume (as arexma seems to and I surely did) a certain level of acquired knowledge about the technology involved. For example, if you don’t know what a codec is, saying to choose one for video compression won’t mean much to you, right? I suggest you post an inquiry in the Basics and Interface section of the forum, requesting links to tutorials about ways to make movies from rendered images.
It also seems as if you could use some basic Blender training, since you were trying to save animations in the wrong file type and are apparently not aware of how to set it up so your renderings are stored where you want them to be, instead of at a default location you don’t know about. Again, ask about tutorials for beginners.
None of this is meant as criticism, just a frank appraisal of your current knowledge of how best to use Blender. 3D rendering & animation is a complicated discipline, so tap into all the accumulated know-how this forum can provide to help you get started. There are a lot of learners here, so welcome to the club!