I'm considering which year of Corvette to buy... Which one is best?
I had a 1973.  
Was that a good year for them?
I didn't ike the chrome rear bumpers. It depends on what body style you like.  The last change was in 2014 to now.
I was thinking about getting the 2021 version. Do you know much about that year model?
Those are sweet and fast too... I believe it's a C7 or 7th generation.
What color should I get?
If it were me, I would go with black.  Yellow's cool too. They all still kinda have that Mako Shark look.  
Haha that's true. I like black. Do they still have the convertible option?
There are C7s that are convertible.  The last I could verify with this short time in 2019.