I used
https://www.immigrar.com/ and i worked with Cecilia.
She was very helpful and we explored all options. Eventually I decided to study and got a student visa. She helped me every step of the way until the moment I recieved my DNI in hand.
After living here for a few years and being much more fluent I got my permanent residency on my own. It was not very complicated. However, I know that if I did not have the help of Cecilia at first, when applying for the student visa, I would have been confused. I highly recommend.