I'm new to all this too. In my opinion, is it depends on the level you are wanting to achieve. The apps suggested are great with very powerful features BUT the learning curve on most of them is very steep (particularly fo a 67-year-old gray matter). Plus, for smooth playback, the computer requirements on most of them are high, needing fast processors, lots of RAM and higher-end video cards for the display. If you are wanting to work with 2.7K or 4K you need a very robust system.
I don't have a system like that and am not interested in spending substantial dollars to upgrade a computer to edit videos I am creating just for fun. I have no visions of grandeur just want to produce simple videos I enjoy watching and maybe sharing with a few friends. For that reason, I have decided to work in 1080 and even some 720 (both workable on my older computer). Not to mention the poor internet access in my area often chokes on streaming even 1080 and anything higher will never work.
You will find most all the apps have a similar interface with the more high powered ones just having many more layers of features and controls. I have looked at a lot of apps but right now I am using VideoPad by NCH. Yes, it is very basic and many people out there will scoff. But it allows you to do simple editing on a simple interface. It works reasonably well on a low powered computer and you can create nice videos. Note - because of my weak computer, clips added need a few seconds to render before they will display smoothly, so it makes the process a little slower.
If you learn the basics with VideoPad - which won't require a lot of time - the concepts will transfer to more sophisticated app if or when you decided to do so. They also have tutorial videos to help with the process although I have yet to watch any. Also, the price is right - for non-commercial use it is free so there is not a lot to lose. I am sure there are better apps out there but for now, this is working for me. (And NO, I have no connection to NCH)
A link to VideoPad -
Video Editing Software. Free Download. Easy Movie Editor.
Just to give you a sample of its output, here is a link to the first video I have created with it. It's nothing fancy. I'm still trying to learn to fly the Mini much less get the great video! -