Welcome aboard
@Nick123 
You can ask 1,000 ECF members what the "best" setup is, and you'll likely get 5,000 different answers!
First and foremost (IMHO) is SAFETY. You don't have to have a degree in physics or engineering, but you should have a basic knowledge of what NOT to do to overdrive your power source. (i.e. match topper resistance with your power appropriately)
From there, it becomes personal preference. There are many styles of vaping - discreet, low-profile puffing all the way to "I'm going to take one hit and fill a 15x20 room with a klowd.
Second recommendation is BACKUPS - it's always advised to have a couple of devices/batteries and a couple toppers. That way, batteries can be charging or toppers swapped in the event of breakdown.
I have a moderate variety of devices and toppers (definitely not the collection like
@BackDoc 
) I have some "relics" from my early days, and a variety of mechanical and regulated mods. Most of my regulated are at least 30W, even though I don't often push them that high. I have rebuildable toppers and "blister pack" tanks (buy a sleeve of pre-made atties and pop one in when it is time to change.)
Form factor - pretty much these days, unless you're going with a very basic eGo stick setup, you're looking at tube mods or box mods. These latter two typically have internal or replaceable batteries. I started with internal battery mods (never bleeding edge, because I am somewhat of a cheapskate) About six months into my journey, I got replaceable battery mods. All mine are for single cells. There are dual and triple battery setups out there (if you ever decide to go that route, make sure you buy the batteries together, charge them together, and use them together. Never split them up.)
I think my "favorite" setup at this time is either the Cloupor Mini + or the eVic VTC Mini and an eGo ONE tank with the rebuildable heads or a Kanger Subtank Mini. I have Nautilus tanks, Kanger Protank 2s, and a couple of different RDAs with which I play. My style varies, so I like to have choices.
Get a device that feels good in your hand, is relatively easy to maintain, and allows for a wide range of vaping styles. You may want to chuck a cloud one day and tootle puff the next
After that, the topper does most of the work. I learned to rebuild coils about 18 months ago, and that has been very helpful (and thrifty) for me.
For the time being, I would steer you away from mechanical mods. Until you have a comfort level with battery safety, I don't condone recommending something that could go "boom".
Good luck and let us know what you pick!
