Whatever. you want to!
You can use your name for the blog, you can call it the name of your first teddy. You can flick through the dictionary and get two random words. You don’t necessarily have to have something relevant to what you are achieving. I’ll give you some examples about website names that mean nothing to their subject but still are huge:
Rotten Tomatoes – nothing about tomatoes here, but a huge audience knows about it.
Bored Panda – do Pandas make websites or look at them when bored?
However some with odd names have gained a lot of traffic due to having odd and possibly unexpected content as bloggers have pulled them up on it and so they have plenty of backlinks due to this (I’ve done exactly the same for them to show you):
Don’t worry nothing sexual on these links!