Whatever sites or apps you use...
ALWAYS ASSUME YOUR PARTNER IS HIV POSITIVE
The one time you buy into the "we're both ddf so we can ditch condoms, you look healthy and honest so we don't have to use condoms"
COULD CHANGE YOUR LIFE FOREVER.
Every time you have unprotected sex, you are taking a risk. Some have taken it with anonymous partners, others - close friends, some - life long partners and have gotten burned. People will have sympathy for the HIV negative person exposed to HIV but no matter how you contracted HIV, whether a casual partner or a lover, many people will no longer have sympathy for you.
I don't say this to scare you from sex or even unprotected sex. Just know what you're getting into. You're too young to contract HIV and you'll always be too young for it.