First time, bad trip, need advice.

A'ight, so the first time i tried shrooms i had no idea what the fuck i was doing, i did them with my brother in my room, and it was one of the worst things that's ever happened to me.

I'm not sure why i had a bad trip, it might've been because it was at night, or i may have taken too many.

I really want to try them again, but i'm kind of afraid, any advice on how to prevent me from having a bad trip the next time?

Also, i'd like to know how much i should take, i weigh about 140 pounds.

Thanks a lot.