personal guides

I have been requesting this topic in the "Tips and Trip Reports" section....so far, nada.
So, until that happy (and long overdue day) I can state that there are many many travelers who frequent this site with opinions regarding recommended guides. All that is requested is......which city are you considering?

Which city? I will be traveling to many cities and thought it would be helpful to have someone in each city to immediately show me the ropes.

There are travel companies that have a network of travel guides, worldwide (Viator, for example). I have no experience with them, but a few travel guides I know are part of their network. Sadly, they take a large commission for arranging your placement with a guide.
If you want to go that route, Viator can probably place you with a guide nearly anywhere you plan to visit.

Thanks to you Blue!

I suggest to look at the tourism pages of the cities you want to visit. Normally they list tours and guides for walking, bike, neighborhood etc. tours.

Example Copenhagen: https://www.visitcopenhagen.com/search/global?keys=tours&ankr-q=tours