I’m jumping into club racing this season and need some expert guidance.
A couple of quick comments:

Good to see you have a realisitc veiw of what it is going to take to get into it. You will have a much better time with it in the long run since your eyes are open at the start.

Trailer - for a long time I used an open trailer. Many people still do. It still is not likely to fit in your single car garage (they are wider than you think), but attracts much less attention parked off to the side. Cheaper, easier to tow (read less truck needed).

Crew - agreed, I rarely have dedicated crew with me and it is fine. Don't let this be a big worry. If you can feed people, you will have friends at the track.

Which car to buy? - go to the track or look at results sheets and see what classes appear to be well subscribed and with what kind of cars. Then look at the prep levels allowed in the those classes to see how much time is needed fixing & building custom parts.

How long are you at the track? - when you're in race group 1 you never have enough time in the morning, but you're all done early in the day. When you're in the last run group you get to the track too early and feel like it will be after dinner before your group goes out. Friday's are for getting to the track, get home all wrung out and tired late Sunday and drag into work Monday w/ a big grin.

We're all experts here!

Good luck with it.