You should definitely get up to Elite in somthing before you buy the Corvette. You'll save hundreds of millions of credits if you outfit your Corvette there.
Why? I bought my Python, Anaconda, Corvette, and Cutter a little over 2 years ago - before 2.1/Engineers and before I hit Elite in Trade. I bought all of them at LYR stations and saved 15%, not the 10% at Shinrarta. All modules were also bought at 15% at various LYR stations.
Shinrarta is for when you want a discount AND have every module/weapon available in the game for sale in one place - e.g, when you're lazy. [big grin]
And yes, I did it back then we people were screaming about how we were making too much money in our Cutters by doing a trade loop that netted 2 million in profits every 10-15 minutes (or about 8 million an hour) by using things like EDDB. You can imagine how amused I've been by all the "exploits" since: Sothis/Ceos, Robigo, Quince, Smeaton, etc.
The OP asked a question. Just give him an answer or not. No need to be judgemental.
OP: As others have suggested, use eddb.io to find a good station. I just checked and there are a LOT of choices, including the one I bought mine at 2 years ago - Ohm City in the LHS 20 system. You'll probably have to fly it/ship it elsewhere to get all the modules with a discount. Have fun!