If you're going to do a half sleeve now but want it to be a full sleeve later, you will need to plan it accordingly. Like if you do a koi on your upper arm then you have to think that everything below it will be in water.
I would imagine that I'm not the only person with a sketch book or peg board of stuff I want to tattoo. I know several people will post designs on their instagram of stuff they wanna do as well.
Tom renshaw, doing realistic black and gray animal/nature has been his thing for longer than most folks have been tattooing. He's in Michigan, which is a little over 5 hours from Rochester.
Howdy, your English isn't that bad. Start doing some visits to shops to look at work that they've done and ask questions. Find someone who you feel comfortable with that can do the tattoo you want.