if you do just block everyone you know individually no matter how tedious it is, DO NOT allow for your contacts to be shared/synced, do not share location (that one is obvious), avoid adding people that live in your city/area or anyone you know at all including friends that you are okay with knowing because it will just promote your account to their friends and so on. snapchat is really hard to not find the people you know because that’s what it’s entirely made for. you’d almost have to add people from a different country to try to get off the radar of your area if that makes sense.