I'm 56 and IMOVIE has worked just fine for me for the past 3 years.
I would like to learn something a little more advanced like Adobe premier
Because it gives you more options and I can do more
But like I've said before
I still use IMOVIE on all my videos
It depends on what you're editing really if it's just vlogs or other simple videos iMovie should work fine. If you're going to be having loads of layers and animations you will probably have a hard time in iMovie.
I still use iMovie even though I'm learning filmora (it's pretty easy, but I've had a couple issues - nothing support couldn't help me with). I like iMovie for the basic edits (like cutting my "um"'s, stutters and babble's out) and using filmora for their text features and transitions (among other things). I'll probably keep using iMovie even to edit my vlogs and (I know it's an extra step) putting the final touches on with filmora. What I like about iMovie is that I can see the audio as I edit, so I know what's been said when certain patterns come up, then I take it out.
Really, I've been using iMovie for the past year (I tried others, but when I came back to use YouTube seriously, they were either gone or not compatible with my computer). It's been great for me. The only reason I got new software is because it can do a little bit more that I think will be useful for vlogs, especially (my usual videos are just product reviews in front of my bed or on the couch).