It's going to be my first time with LSD soon, too.
After research and my experiences with various other drugs, including other psychedelics, I wouldn't consider going anywhere near a dose level you have considered for the first time. I'm going to do 100-200ug of what I know to be good quality LSD, waiting for a suitable day and deciding the final dose on the day, based on how I feel and any other considerations I need to take account of at that time (how much time I'll have, setting, etc. etc.).
Just for a moment, I'm going to pretend this (or any other) new experience is like getting a date with a girl I've been around and admired for a while.
Leading up to the date, I might think through what's might happen on the night. In my mind, everything will go perfectly, we'll get on fantastically and I'll want to do everything with her that night because I know she's the one for me and will be everything I want from a girl. I'll be so satisfied after my night with her, I won't need or want to see her again. We'll go our separate ways and I won't be bothered if I ever see her again.
In reality, things don't often go the way you'd like them to. In reality, I might make a move on her and get slapped around the face. I could find out something about her that really puts me off. We might turn out to be completely incompatible. Trying to get to final base on the first night is usually not the best way to approach a long term relationship. It can happen, but in my experience I've never set out to do it and if I try it usually goes wrong.
Of course, it might all go the way I'd like and we end up having a wonderful time together. Why would I never want to see her again after a night like that? It makes no sense to me.
My advice would be to play it cool and not run the risk of having a bad time by trying to do everything in one trip. Take it slowly, pace yourself and when that ultimate orgasm happens, you might find the journey getting there has helped it to be more enjoyable and easier to cope with.