The battery should be pretty good even tho you could do a lot better.
Go to fasttech site and search ego and you will find plenty of them.
Now for the question of the tank, looks like it come with CE4 tank. Which is top coil cleromizer (juice delivery system).
May not have the replaceable heating coil as the attached picture. This one is CE4+ or CE4s as they are called.
I would suggest you guys (newbies) try out the EVOD (tank , juice delivery system), which are easier to fill, better vape and very easy to maintained. Get some spare heads (try 1.8 Ohm) and you will be sure have a good time.
Here are some samples. https://www.fasttech.com/search?evod
You can order from anywhere, just a site I used is linked.
Cheers and happy vaping......