Ask HN: Best on-site courses for machine learning or pentesting

It seems I could be able to spend a couple of months next winter to concentrate pretty much full time to learn something new, and machine learning and infosec are quite high on the list of things I think I'd want to tip my toes a bit deeper. I know there are a lot of excellent on-line resources for both of these, but actual face-to-face classes and peer discussions are something I think I would like.

So, what would be good on-site courses/certificate programs/whatnot that I should have a look at? (Can be anywhere, including places outside North America, I am also willing to pay money for quality, but I do not want to pay just for the prestige.)

Does the recommendation change if I am just trying to fulfill intellectual curiosity or looking for an actual career change?

Or is my best bet actually to just go somewhere alone for a couple of months where i am not distracted, and take hackthebox and/or kaggle seriously for a while?

As an example, I have been pondering the fast.ai certificate courses at University of San Fransisco.

On the pentesting side I have tried to look at live course for OSCP, but haven't found anything convincing so far. (A couple of day's course feels a bit short to actually deliver but maybe I am wrong?)

(I have somewhat technical background ,so I'm not looking at things where we start from print("hello world") and I can code fizzbuzz, know what is nmap, sqli and backprop - at least in concept level... And I am willing to put some work beforehand if there are pre-requirements that I do not yet fulfill)