There are really no skill levels. Basically it is just time and experience. But here is something I have noticed:
Most of us started with an 808 or similar. But you find carts with filling a pain, so we moved to tanks or similar. From there it comes down to how much money and time you are willing to spend. Don't start off with VV or expensive mods, start with a basic setup that gives you plenty of choices. An ego batt is probably the most versitile, but you can get an adapter for alomst anything to anything. That said, an ego batt will give you lots of choices so you can try different types of carts, tanks, etc, in an effort to find what works for you.
This is all about "personal" preference. There are many vets that don't use vv or expensive mods because we have found something that works and stay with it. Remember that your initial outlay will be fairly high for equipment and liquid as you find out what you like and what works best for you. Some will spend lots of $$ for stuff that might not work for you. Being a veteran doesn't mean that you have lots of toys, but that you have been around, seen and heard alot, and know what works for you. It just takes time. I sometimes envied the guys that started vaping with an ego-t, but when I started they didn't exist and I just plugged along with my 808 until it did.
Once you find something that works for you , then you might consider DIY. Sometimes it isn't the equipment, but the liquid. I am mixing a 95%VG liquid that gives me tons of vapor, flavor to my liking, in a system that is easy for me to use (batts recharge quick and last me all day, I have plenty of cart/tank options, and it is highly portable). Of course I try different stuff, like the new stardust, but I have my goto stuff that I know will give me vaping enjoyment.
Remember that it is all the same basic idea: get juice to a coil, get power to the coil, create vapor, repeat, clean, start again.
Choose a system, get extra batts, try different feeder styles and different flavors/liquids, and you will be there before you know it.
Saludos