ok first look up ohms law and understand it
by understand i mean learn how many amps your battery produces, so figure out what the lowest ohm you should build on your device that wont draw more amps then your battery provides
OTHERWISE YOU CAN GO BOOM
use steam-engine.org to do the calculations
then find a simple to use rda
a recommend a petri clone off ebay. usually about 15 bucks
good flavor good clouds and CHEAP
and easy to use
next decide - build the coil yourself or get some premade wires
premade wires can be had cheap on ebay and other websites. you can actually find variety packs so you can try multiple types of coils for cheap (twisted,claptons,aliens, etc). then when you find what you like you can start making your own and experimenting in diameter and number of wraps to change your ohms - just make sure you know the safest build you can us ewith your mod and batteries so YOU DONT GO BOOM
next learn how to wick - watch youtube videos of the rda you bought
then experiment from there