Until you know what type of tank or atty you like, I would stick with the lower priced battery's with both EGO and 510 connections. Look for Spinner by Vision, Twist or Winder. I have had good luck with Spinner, but they are pretty much the same. You will need two batteries to start and a charger which you should be able to find in a starter kit. Spend a little extra money and get the largest battery, 1300 mAh. Buy one or two each of different type of tanks including both top coil (like iClear 16) and bottom coil (BCC) like Ismoka BCC, Arrow or Aspire. Pay attention to the type of threads they are compatible with, EGO or 510. The EGO type will look more integrated on you EGO batteries. If you are going to be sampling e-juice, then pick up a drip atomizer. You can try a few drops in the atty, rinse, blow out and try another. I would also keep your tank size down as a second phase of exploring e-juice without having to go through 5 or 6 ml if you end up wanting to switch.
The hardest part of beginning vaping is finding the juice you like and the tank or atty to go with it. After that you can explore mods and RBA/RDA's.