What Not To Do!???

I recently found out that I'm expecting and this will be my first. I haven't made it to the OB/GYN yet but, did make an appointment. I just want to make sure that I don't do anything to hurt my baby. I really don't have anyone to talk to because my boyfriend wants to keep our pregnancy a surprise, and I agree because of the situation, so I haven't told my mom yet and I feel like I'm missing out on vital information that I need to know. Any tips would be great, Thank You!