I would add to that a suggestion of getting a small digital scale so that you can weigh stuff rather than measuring with syringes or trying to use the drop method (drops are not a good way to measure since each liquid has different number of drops per ml). For calculator, I like the free e-Juice Me Up. It's pretty straight forward. And, you'll want to learn about acetoin, diacetyl, and acetyl propionyl and know if it's in your flavorings or not. Diacetyl causes respiratory illness (bronchiolitis obliterans aka popcorn lung, only known treatment is lung transplant for severe cases). Acetoin and acetyl propionyl are ingredients of concern, with acetyl propionyl believed to be as bad as, or even possibly worse than, diacetyl.
Regarding nicotine - do NOT purchase pure nicotine unless you have the lab equipment to use it safely (hazmat suit, glove box, etc). Most of us use 100mg nicotine base. Even that has to be handled carefully, kept away from pets and kids, etc. because it too can be harmful or fatal.