If you dont have much experience with combat, buy a Viper mk3. Then fly a lot of hi-res. Do that for a bunch of sessions, and only then upgrade to an expensive ship.
In my opinion the Viper isn’t a good starter ship for combat.An A-rated 3 million credit Viper (plus rebuys) is a good place to start going to Low/High REZ sites. It won't take out every ship but you'll have System Authority ships helping. Also great for getting a Pilot's combat skills up and running.
Buy a Chieftain.
Shoot stuff with it.
A lot. [up]
^This - Mine costs around 74 mill, plenty of change the get yourself a Viper III & IV. My Corvette costs 601 mill, great ship but I rarely use it, sleep inducing unless you want a quick kill for an assassination. Nearly 4 years in a Viper and I still find it fun, especially in open play, the rebuy is peanuts.
Spend it all on a Python, fly without rebuy, get destroyed, lose it all. Then come back and post a rage thread.
It's a forum tradition.