Pretty simple. Open the folder with the file, then open the file with your choice of media player. VLC is what I use to view. My laptop is not for 4K so the video is choppy that I view. If I am not doing 4k video, then the playback is smooth.
As for editing what you have, it's a personal preference as to what you like. Just read all the fine print about the software you are going to buy to make sure it does what you want. There really is no software that does everything perfect. Most do one thing really good and throw in extra features as a bundle. For me I have about 10 I use as they all have different features I like. Not saying you need that many.
There are a pile of people on here that have been editing their footage, and will also chime in with some great advice. Just take it all in and do the research from there.