And im guessing i probably need those electric meter things that show some kind of number that i see in those vids?
...OR a battery unit that shows you the ohm rating of your coil (most variable wattage devices - like many that have been listed in this thread - do that now) ... OR a standard multimeter, assuming you don't intend to sub-ohm, but yes, if you're going to rebuild, you need something to test the resistance (ohm rating) of the coil you build.
Honestly, though, if you don't want to learn to rebuild coils and wicks you probably shouldn't as you'll just be fighting it all the way. If that's the case, you might be better off using equipment that is more or less disposable and just accept the additional cost of replacements. IMO, rebuilding is for people who want to save some money and who don't mind tinkering with stuff -- and who have the time to do so. I rebuild, but I have the time and I find it interesting. Some people just don't like doing it. Nothing wrong with that.
Look at it this way. ALL coils - the part that heats and vaporizes your eliquid - in ANY system, WILL eventually go bad and eventually become useless. Likewise, ALL wicks WILL eventually clog and eventually become useless. When the coils and/or wicks go bad, you can only do one of two things: buy new ones or rebuild them.
If I understand the G6 system correctly, each of those disposable cartridges contain both a coil (that heats and vaporizes the eliquid) and wicking (that holds the eliquid and brings it to the coil). When you replace a disposable cartridge, you are basically throwing away the old coil and wick and installing new ones. It's convenient, but you pay for the convenience. You can reuse some of the cartridges to some extent by refilling them, but the cartridges WILL eventually go bad and WILL have to be replaced. (I wouldn't even think about rebuilding those...)
Members here are suggesting that you rebuild primarily - I think anyway - to save you cost of buying ready-made coils and wicks. However, it will take some time and effort on your part to learn how. It will also require what in my opinion is a relatively reasonable investment in materials and equipment - all of which you will easily make back over time by not having to buy pre-made coils and wicks. (I probably shouldn't try speak for them, but that is what I think.)
Again, if you are going to vape, coils and wicks MUST be either (1) bought ready-made and replaced by you, or (2) rebuilt by you. I'm not aware of any other alternative.