If it cost $2, it's probably not a standard cartomizer. Is there any writing on it? What does it look like?
Try a Ego pass thru with a vivinova tank with some spare wicks and a bottle of juice. Probably around $60. But great start. The only bad thing about it is that the vivinova might be overshadowing the ego but it is a great way to start. I started my friend off at that and he loved it.
On a side note. What are some popular juices? Flavors
Hard to explain it concisely. On the evic, it will be better for you to only look at watts for now. 5.1 is lowish and won't give you a lot of satisfaction. Your sweet spot will probably be somewhere between 6 and 8. Turn it up a little and vape for a bit. If it gets better, dial it up again. If the taste starts to get a bit burned, dial it back down. Once you find what works, you probably won't need to change it again for this atomizer and this e-liquid.