Hi Jane - welcome!
You didn't really ask for recommendations (yet), so I won't give any, but tell you what I use & how I got there:
I smoked many years, and wanted something to replace that style - MTL.
So I started with an Aspire Zelos kit, and decided to start building rta's. Went thru all the Kayfuns (liked the Mini 3 best), and several other atty's. Now I use SXK and SJMY Doggystyle RTA's only. Currently using them on Sbody Macro DNA 75 mod, Wismec P80 mod, and Artery Nugget mod. I think mods make only a minor difference in the quality of vape, so I spent most of my time getting the right tank & juice for my style. I use only tobacco flavorings, and started with Halo Tribecca and Indigo's Duke, mostly. Now I make my own juice, from Stixx Mixx - a naturally extracted tobacco flavoring, which if you like tobacco, you'll find NET's are the closest thing to smoking (only better!). I was just thinking today that if I started with what I'm using now, it would've been SOOO much easier! But we all start with something, experiment, and then hopefully find our sweet spot.
Good luck - don't be afraid to ask specific questions, and you'll get a lot of great info here!