You can get condoms for free from any YPF condom distribution point. Check out the map for the nearest place to where you are now.
For all the other methods, like the pill or implant, you need to speak to a nurse or doctor who will advise you on your choices and can prescribe contraception to you. You can also receive more information from any YPF clinic.
Some contraceptive methods, like the implant or the injection, must be fitted by a nurse or doctor. Sometimes this means that you have to book an appointment. It's a good idea to call the clinic beforehand if you think you might want to start on LARC (Long Acting Contraception).