As long as you have researched it doesn't really matter what you get as a first snake (within reason).
Commonly corns are advised as first snakes and if you go to a rep shop theyre likely to sell a corn as a starter.
I got one, then three weeks later I bought a 6ft boa! Then a 7.5ft boa, then another corn, then a hognose, then a burm!
It won't take long before you have many and all the ones you considered starting with. Its a very strong addiction.