I have grown up as a swimmer so I am used to showering with my trunks on, I am now going into the army and am very self conscious. I never tend to look for obvious reasons but it is normal in men to have hair on the testicles and bottom yes. An odd question but I have never known and don't want to be the odd person! Any help is great.

Its not an odd question if you've only been around men who shower with their trunks on. I've been a swimmer since I was a kid so I've been in a lot of showers, mostly without trunks and there is not really anthing novel about it. The amount of hair men have on their testicles and bottom varies from guy to guy. Just as the amount of chest or back hair varies.
I can appreciate that you are going to be self conscious but quite honestly you probably don't have anything much different under those trunks that the other guys you'd be showering with. Some of them are going to be just as self conscious as you, you just won't know it.
Relax and just get in the shower, do your thing and get out. After a while the novelty of all naked hairy butts will wear off and you won't even be thinking anything about it.

You will find some do, and you will find some don't have much, other will look like they have fur. Some may shave thiers even.

But it is normal and not a odd question, you will note that unless things change, there is no privacy in the military basic training, so you and a bunch of guys will be very open with each other, but you will be so busy that you will not have a lot of time to worry about it.

Hey there, I am a swimmer too, and I could see how this could be awkward for you. My freshman year of high school, I learned quick to get comfortable with naked men around. At summer band camp, all the upper classmen were naked and would/will laugh at people who wear swim suits, also on swim team, we all changed together, showered together, and were naked. No biggie, it's important to know that everyone has the same thing, and you can't change yours. Hair is there, some is more... noticeable that others, and I for one, since I swim year-round, shave my genitalia, so I wear a suit during aquatic-fitness (A gym class in high school) so that the non-swimmers are not weirded out. Don't be worried about it, just remember you have what they have, and it's not going to change.