At my work they have a old setup i google tag manager from 5 years ago – almost all the tags are outdated and some of them are not working.

What is the best course of action? Delete them all and start from scratch or try to fix them?

I should metion that we are getting a new webisite, however there is no constent mode active and there is still a couple of months let before we get the new website.

I´m kinda of a new in GTM, so im not sure what is best thing to do?

I have not tried anything yet, but i have downloaded a backup of the tags and setup.

I feel like deleting them all and starting from scratch is the best thing to do, but is there something that would / could cause problems?