Redirect URL or Move Site?

Hi everyone, I have a bit of a dilemma…

I have an old website that’s been up and running since 2007, lets call it: https://www.mickyssite.com (just an example)

I also on the same webspace/server have a new version made in wordpress with all the content ported over, this currently sits up and running at:

https://www.mickyssite.com/beta (again just an example URL)

I would like my ‘beta’ site to takeover from my old site at the main URL and was wondering weather I would be better moving the new site from its /beta/ folder to the site root, or re-pointing the main URL to the /beta/ folder?

I would also like to know what precautions I would need to take within WordPress before and after taking either action?

There are many articles about moving sites over to other domains but nothing that seems to apply specifically to my situation.

Many thanks in advance for your help! ??

Mickey x