Best advice is ignore anyone who suggests they'll make you a star quickly, and contact other models direct by pm here to ask their opinions about people you might be working with. Finally, do nothing you don't want to do and always try to work with people of a higher standard as you progress but accept that many amateur togs will pay a fee and be fun to work with.
1) Don't be put off by the dozens of messages from photographers who want to "help improve your portfolio" for free.
(I introduced two new models to this site and they both received a LOT of 'helpful offers' in the first couple of days)
2) Relax your eyes when you look at a camera. Practice in front of a mirror.
Experience, experience, experience .... just get out there and shoot with photographers whose work you like. It is better to do TF shoots with good photographers because they will guide and advise you and get you great images for a portfolio. You will then be able to market yourself for paid jobs.