It can be great to chat with new people online but you should only add people that you trust offline (like family and friends from school) to your friends/contacts lists. Once you add someone to your list, they may be able to see more of your personal data or contact you whenever they want.
Never share sensitive (such as your address or date of birth) information and don’t agree to video chat or livestream with someone you only know online. You never know who this person really is nor how that person might behave in private and they could say/do things that worry, upset or even endanger you.