Hello and welcome to the forum Cazzie. Glad to have you here!
If you are looking for an upgraded setup here are some possible options for you to consider:
A variable v/w (twist/spinner) is usually recommended over a "non variable v/w" battery. It allows you to adjust your settings to get a better "vape". Some flavors taste better at higher voltages than 3.7v
1. JoyeTech Ego-C Twist
2. Vision Spinner
3. Innokin iTaste vv v3
4. Innokin iTaste MVP v2 or MVP 20 watt (the latest edition)
5. eLeaf iStick
The first 3 are fall into the "ego style" category of battery (with variable voltage). They range in size from 600mah to 1300mah. The higher the mah the longer the battery will last between charging.
The 4th & 5th ones are a step up from an "ego style" battery in that they are smaller variable v/w box mods with a very big battery (2400-2600mah). It will last many vapers a whole day before it needs recharging. The MVP is probably one of the most popular
batteries for someone upgrading from an "ego style" battery. The iStick is newer but it too is very popular.
I suggest buying only
name brand Joyetech Twist or
Vision Spinner ego batteries. BTW, "ego" is merely a type of battery, not a brand name. Buying "generic" ego batteries is always going to be hit or miss...mostly miss.
You will need to purchase a tank (the juice attachment). The mini Nautillus, mini Aerotank or regular size Aerotank (all made of glass & all have adjustable airflow control) are very popular.
Why would you want a glass tank (you may be thinking to yourself)? Here is a great resource regarding "tank cracking" eliquid by ECF member Baditude:
Something Safe for Cinnamon and Citrus Flavors