Disclaimer: Being that LSD is an illegal substance I can not explicitly encourage you to break the law. At the same time I understand the experimental factor. You will make your own choices and information is your friend. Make choices you can benefit from. Be safe and enjoy life.
Taking LSD can be an adventure. I used my first trip as a tool of acceptance of who I am. I bravely stood in the face of the person I had been up to that point. I felt like it was ok to be me and that the people around me wished for me to be free too. After that original trip I did it several more times but mostly because of the people I was around. I didn't learn much more and in fact, it started to become kind of boring so I just didn't bother anymore after my sixth or seventh time. But it can be a good thing in a safe environment with people who make you feel good.
If you have siblings with mental illnesses don't drop a shit ton of acid right off the bat because mental illness is partly genetic and when a person is on acid it's basically like a controlled psychotic episode (sort of). If that is the case and you still decide to do it start with a low dose like a quarter or half. It can take up to 45 mins to an hour to feel the effects. Which you won't notice till you are actually tripping. You might feel lighter or a little giddy. That would be signs that it is working.
I had to help some kid down from a trip that was starting freak him out. He didn't know who he was, where he was or what was going on but when I asked him what kind of cigarettes he smoked he readily said, "Camel Lights" so I said "Ok man. Come with me" so we got up and walked to some real weird carry out that had all these crazy do dads in there. I bought him a pack of smokes placing them confidently in his hand and looking him square in the eye I said, "ok man. I guess I'll see ya around" and walked out with out him. An hour later I saw him happily playing frisbee and he came up to me and was like, " hey man, thanks a lot. You helped me get the dose of reality I needed to keep it together"
Moral of the story: Reality will be there when you come down. It's out there right now. Be a part of it. Experience it.