I live in the Pacific Northwest so I can't recommend specific shops.
However, reading between the lines it seems you would rather go short than to go long. Resist the urge to go too short. You'll learn the fastest by getting up on a board rather than struggling to learn on a short board.
I started out buying a 9' longboard that was more tuned for the performance oriented longboarder (less wide and less thick than most and the rails more for performance rather than flotation). As a longboard, it wasn't the best choice. I should have gone with more flotation. With my 160 lbs. plus the weight of my wetsuit, the board just barely floats me. I like the board now, but in hindsight I think I would have done better with a funboard or mini-mal that has more flotation as a board to actually buy. Only slightly shorter, maybe 7.5 to 8 feet. I typically surf in an area that is very windy, and carrying a longboard down to the beach is like trying to struggle with a kite. Also the funboard length would be easier to manage in the water, easier to transport, and easier to store.
My suggestion is to rent a longboard to learn on at least for a month or so. Typically a surf school would put you on something huge and floaty. If that's good for a surf school, that should be good for your first rental.
Then decide if you are a longboarder at heart or not. If you feel you want to go shorter, then you might want to buy a funboard size to keep for years. Even if you learn fast and transition down to shortboarding faster than expected, you'll be glad you have a nice funboard in your quiver for smaller days. Go shorter than the funboard size when you feel you have mastered it. Then make the decision if you want to step down slowly in size or go right to shortboarding. But keep the funboard.
You can find a surfboard size chart for weight and skill level of surfer on this site.
Try this chart:
https://surfing-waves.com/board/board_size.htm
Or look at this size discussion:
https://surfing-waves.com/forum/viewtopic.php?t=2305