I have no idea how and how to avoid STDs and stuff.
Hi, and good on you for writing in.
It sounds like you care about your health and want to keep yourself safe.
There are different types of sexually transmissible infections (STIs; also called sexually transmitted diseases or STDs). They can have different symptoms and be passed on through oral (e.g. head), anal or vaginal (penis-in-vagina) sex. Some STIs like chlamydia don't have any visible symptoms, so it's possible to have chlamydia but not know it. Other STDs such as genital herpes can be passed on through genital touching (e.g. fingering, hand jobs). STIs like chlamydia or gonorrhoea can be passed on when body fluids are exchanged (e.g. oral sex).
The best way to reduce your risk of getting an STI is to use condoms and/or dental dams (thin piece of latex) for any and every time you have oral, vaginal and anal sex. You can buy condoms and dams from supermarkets and chemists, and condoms also from service stations and sexual health or family planning clinics. You can also buy flavoured condoms from supermarkets and chemists, which are often used for oral sex.
A good place to start is for you and your boyfriend to get tested for STIs. To get tested you can visit a doctor or a sexual health service in your local area. You can ask to see a female doctor or nurse if you like. Remember that these doctors and nurses deal with these issues every day, so there's no need to feel embarrassed or worried about seeing them. Have a look in the Somazone services directory for one near you.
All the best.