COTH’s article about exactly this:
https://www.chronofhorse.com/article/so-you-want-to-try-foxhunting-now-what/horse.
I know all three businesses and they are absolutely reputable and have lovely hunt horses.
I got back into hunting five years ago riding a hireling at Betsy Parker’s Hunter’s Rest. I highly recommend her. She is also the third filight field master at Old Dominion Hounds, and she tailors the route and speed of the third flight to guests and whoever else is riding third that day. Heather Heider and Jennifer Taylor are also excellent, I just have more first hand experience with Hunter’s Rest. The joy of stepping onto a made, schooled, fit, perfectly behaved hunter can not be overstated. It allows you to truly pay attention to the countryside and the sport because you don’t have to worry about your horse.
Re: Imposter syndrome. Do you ride out cross country at home? Are you comfortable riding out with a group? Then all you need to do is familiarize yourself with some hunting etiquette and you’re good to go.
If you are worried about clothes and turnout, most hunts have relaxed expectations for guests and new foxhunters. No one expects you to spend $1000+ on hunting kit just to try it the first time. My hunt’s requirements for guests are any tall boots that are black; reasonable half chaps with paddocks are fine. Any riding coat as long as it’s a dark, conservative color. Safety headgear, always, and black wo bling is preferred. A stock tie is a nice, cheap upgrade, but a collared show shirt is acceptable. We want people to come out, have a blast and fall in love with the sport, not worry about their clothes.
The people who hire hunt horses usually have a lending closet of appropriate clothes to boot.
I bought my tweed coat at a consignment shop for $40; I found my black melton on ebay for $100.
Please ask me any other questions you might have! I want you to go hunting and have a fabulous time!