Help protect my privacy

Hi my parent wants to get me a computer which is nice, but in the past my parent has monitored what I’ve done and read my messages without my permission now I’m an adult (30) and I don’t want this intrusion is there anyway to make sure there’s nothing on my new computer?? I feel this is a massive violation of my privacy and boundaries and don’t want to deal with this.

adult computer don intrusion messages nice nothing permission privacy protect