Sneak out ! HeLp ! (read description)?

so anyways, I really want to be able to sneak out with my friends next school year (right now it's summer) but i need advice on how to make my parents' think im still home...excuses if caught...and how to get in and out because we have a alarm system that beeps when you open the garage, front, or back door! btw our windows do not have alarms but I live in a two-story house and DO NOT want to jump out a window yet!! i could disarm it but at random times during the night they will come downstairs to get a snack so they may notice if it's disarmed! my dad also goes in the garage at night time to smoke sometimes if the door doesn't beep he's gonna get suspicious!!! so how can i avoid the beeps ? also my dad wakes up at 3:30 am to get ready for work!!!IF YOU CAN ANSWER MY QUESTIONS WITHOUT BEING RUDE THEN CHU R AWSOME <3