Getting nails done for the first time

Hi! Looking for some advice on what to ask for - I have never gotten my nails done, but wanted to try it for prom/grad. I have very short/tiny nail beds and they are quite short. I'm just looking for a simple almond design that can add some length to my nails. I'm just confused between gel, polygel, and acrylic? I've heard that gel nail can harm the nail bed, but if anyone with more knowledge can speak to this? Thanks :)