Hi Rita. The multipart guide in the ECF Library will help you get started. Just ignore the superminis in it and since I started on M402 and M401 I recommend you ignore them too. The smallest decent ecigs are Joye 510 and KR808D-1 (Vapor4Lifeis KR808D-1 as is Smokeless Image which is a different model). Most people here use and recommend manual
batteries.
Ans the guide does not show them but there are bigger fat battery models (like Ego and Riva 510) and
mods that can provide much longer battery life and the ability to use hotter atomizers and cartomizers. Some people like to go right to the big models.
The ECF Library
All need eliquid unless you are rich and can afford to throw away multiple carts per day. The upper seedy crist of ecig seller is full of lies and bs and ripoff prices, so beware. Don't buy anything unless you know what Chinese model it really is, whether it is a good and compatible model, what it should cost, and where else you can get parts and supplies for it.
The most popular slim starting models are Joye 510 manual (and its larger mega xl size) and KR808D-1 manual (and two good rebranders for the latter are Vapor4Life and Smokeless Image). If you decide on a 510 only buy Joye brand because there are some shoddy and electrically incompatible clones. 510 is a 3-piece but there are plenty of blank cartomizers to use it as 2-piece (preferred by most for their favorite juices). KR8 is a 2-piece so there are plenty of prefilled cand blank cartomizers but no atomizers (on a manual KR8 you can use a DSE901 atomizer and drip tip to test juices). I think Joye 510 w/ a Boge carto is a moister more vapory hit, KR8 is is a dryer hit with more throat hit.
As you look at ecigarettes, 100mah is about 1 hour of moderate
vaping. Decent ecig shops list the mah of their batteries. two popular shops are Liberty-Flights.com and LiteCigUSA.net, and for KR8 as I mentioned above Vapor4Life and SmokelessImage