Filmora has good reviews, and would likely be a good choice.
The computer does make a difference but not that much. I upgraded my HP with a NV Me M.2, 500 gb drive which does give faster processing. I shoot my drone video in log
(except the MIni 2, )4K-30 or 60, but usually output in 1080 since most people will view it on a tablet or phone. I make a personal copy in 4K that I can view on my 56 inch Samsung but I really don't see much difference. The TV may be upscaling the video.
I do offload all created videos and associated files to an external drive because they really eat up space and can bog your system down.
Good conversation. I could have used this input when I started . HAPPY NEW YEAR EVERYONE