I'd recommend trying to find a place with qualified teachers. I went to a Goenka retreat (i.e. dhamma.org) and there were some weird things about it: all the teaching was done through 30-year recordings of a guy who's been dead for 10 years. The facilitators actually present at the retreat were his "assistant teachers", and in my case they didn't seem to have a lot of expertise. They seemed to be following Goenka's script and were reluctant to deviate. I think everyone there really meant well and had no ulterior motives, but there were cult-y vibes nonetheless. If you can put up with that and are willing to work through difficulties largely on your own then maybe I'd recommend it. I had a great experience, in the end. The food and facilities were also quite nice.
Also, I had some intense experiences that I would have thought were only possible with psychedelic drugs. It really scared me at one point: I was sure I was losing my mind. I almost asked to be taken to a hospital and put on antipsychotics. I think there is a chance that if I had done that, things would have gone very badly for me.
The other people on the retreat with me apparently did not have experiences like this. But it's not unique to me. [1]
Just go into it with an appreciation that you're attempting something significant and powerful and probably (at least for now) a bit outside of rational understanding.
It was worthwhile for me. I had a hard time justifying taking 10 days away from everything, but ultimately I convinced myself that it would be exciting to spend 10 days doing something wildly different from what I've done basically every other day for the last couple of years. Variety of experience is a good thing, right? :)
[1] https://www.brown.edu/research/labs/britton/research/varieti...
