If you fancy trying your hand at using a full professional video editing suite, and don't mind the output resolution being restricted to 720p HD, give the free version of Lightworks a try. Other than the restriction on output resolution, the free program is much the same as the full 'Pro' version (£249.99) that's been used to make such films as Pulp Fiction, LA Confidential, The King's Speech and The Wolf of Wall Street:
https://www.lwks.com/index.php?option=com_lwks&view=download&Itemid=206&tab=2
At a similar level, DaVinci Resolve 16 (which is also free) is popular with many users, despite its steep learning curve. (It's the free version of a program that otherwise costs $299)
https://www.blackmagicdesign.com/products/davinciresolve/
You can read about those two programs here:
https://www.macworld.co.uk/feature/mac-software/mac-video-editors-3697211/
If you want to keep things simple though, use either of the two big open source cross-platform video editors, which are totally free and without any restrictions on their use. Shotcut is possibly the best known
https://shotcut.org/
but OpenShot is good too
https://www.openshot.org/