You're going to get a lot of personal opinions based on your question. I think you need to narrow it down a bit. Here's some questions and options to consider:
1. Do you want a stick battery (form factor) or a larger PV/APV, i.e., like an ego battery (iTaste 3.0, KGo, Twist, Spinner, Winder, etc.)?
2. Do you want a tube type battery or a box mod type battery? This is strictly personal preference as you can find similar performance and characteristics with both types.
3. At a minimum, I think you need at least variable voltage and an Ohm meter for your device. Without them, you're practically defunct before you start.
4. What is your budget, or budget range? Recommend that you get the best device for the money/budget. There's some great values out there. For example, the Vamo has practically all the features you could want in any APV, and it costs only $30 - 35 (recommend the stainless - a bit more) as an express kit, and about $50 - 58 as a kit with batteries and charger.
5. Do you want to be able to use different battery configurations, i.e., 18350, 18500, or 18650?
6. Do you want the device to telescope (to accommodate different battery configurations)?
7. Do you want variable wattage?
8. Do you want replaceable/rechargeable batteries, i.e., separate batteries, not built in batteries?
9. Do you want USB charging?
10. What kind of battery life are you looking for?
11. Do you want ego threading and 510 threading, or just 510 threading (there are other, less popular configurations available)?
12. What kind of topper are you using, or going to use? Clearomizer, Cartomizer/Carto Tank, Dripper (RDA), or RBA? What have you used so far?
13. What kind of juice are you using? Not a big determining factor early on, but it can affect choices in some cases.
14. What is your vaping experience and knowledge so far?
15. Do you want a kit (often less expensive), or do you want to piece it together (allowing optimum selections for each piece and often costing a bit more)?
16. Whatever you would like to add....
There is a typical sequence and evolution on setups that we see here all time. It is not cast in stone by a long shot, and the sequence is certainly not sacrosanct, and I include this more or less to show an example of several of the more common evolutions seen on the Forum every day:
Batteries:
Cigalike => Fixed Voltage Stick Battery (Ego-T) => Variable Voltage Stick Battery (Ego-C) => APV Stick Battery (iTaste 3.0) => Entry Level APV (Vamo is perhaps the best "value" entry level APV) => More Advanced APV (SVD, MVP 2.0, Sigelei V3/V5, SID, etc. - great variety in the $35 - 80 price range, and lots of options) => Very Advanced APV (eVic, etc.) => Most Advanced APV's (Provari, Semovar, REO Box Mod,etc.) => Mechanicals (can be anywhere on the timeline and learning curve, huge variety, huge price range, lots of clones now available)
Toppers:
Dripping Atomizers (huge variety) => Most Basic Clearo (CE#) => Top Coil Clearomizer (Kanger T2, Vivi Nova, etc.) => Bottom Coil Clearomizer (EVOD, Protank II, etc. - very popular on the Forum) => Cartomizer (Boges, Smok, Ikenvape, etc.) => Carto Tank (SIBTanked, Phiniac, etc.) => Drippers (Igo-L, HH357, Origen, and countless others - huge variety and huge price range - aka RDA's) => Rebuildable Atomizers (Gennies, Kayfun's, Ithaka, their clones - huge variety and huge price range, lots of clones now available), etc.
These "timelines" and evolutionary possibilities represent examples only, but I'm including them here to give you some idea of the options, the learning curve, the variety, and the type of upgrade decisions that we see here every day. There is no one way, some people never upgrade, some people start at the top, high-end gear, etc. Anyway, my two cents. The more information you give us, the better we can help you in your VapeQuest and GearQuest. Truthfully, gear selection can be far easier than juice selection (JuiceQuest). Juice variables can include:
1. Nicotine level (0 - 36 mg/ml)
2. Ratio of PG to VG (PG/VG ratio - generally VG is thicker and provide more vapor, PG is thinner and provide more flavor and throat hit). Popular ratios include 50/50 - 80/20 PG/VG, but all configurations can be found)
3. Flavor - completely subjective. Three options:
a. Sampler Packs
b. Brick and Mortar Juice Bars
c. DIY (less expensive juice cost, expensive start up cost. Need good recipes and juice calculator. More an art than a science. Lots of YouTube videos on DIY. Care must be taken always when working with nicotine.
Anyway, my two cents. Good luck on your Journey. Hope we can narrow it down once some of the questions are answered. I started with the cigalike in 2009 and now vape with Provari's and carto tanks, samovar and kayfun. Vaped for months using clearos like the evods and Protanks. Protank II may be the best clearo, imho. Sigelei V5 may be the best under $100 APV, imho. YMMV and gear is more subjective than certain. Focus on features and budget, and it's fairly easy to narrow down. Best to you and Happy Shopping! Power up and Vape On!