Markets with a lot of activity and, ideally, going through gentrification, are generally the best markets for flippers and wholesalers. There are many of these markets in nearly every part of the country. We're seeing the most activity in the areas you would expect; texas, tennesee, north carolina, florida but we're also seeing strong demand even in areas you wouldnt expect, like Boston.

Good luck on your journey.

is better doing it virtually or should I start in my state? in in NJ 

The market YOU are most familiar with, is where you should start. You'll know what numbers investors are looking for in certain areas and you should be more able to recognize a good deal then

Agree with @John McDonald. You want your market to have a strong population density, where demand and growth are imminent.