The good thing about ecigs and vapes aside from being safer compared to typical cigarettes is that there are a good number of available flavors found in the market. Choice is not something you will be running out when it comes to e juice. First thing to consider is the ratio of PG or Propylene Glycol qualities or vegetable glycerol VG. You may start with something that has a high ratio f PG because your taste buds may want that familiar flavor of nicotine hitting your throat. Burn Smoke Shop is one of the authority sites on this topic.
As you get use to it, you will begin to find something that will fit your preference. Nothing will go wrong if you go experimenting on the flavors and mix two flavors or three. If you do not have the time to do any of these then you can just choose from the wide array of cheap e liquids found online. When it comes to nicotine content, it is also something that can be adjusted. There are ejuice vendors who are selling authentic products with different nicotine rates.
If you are a heavy smoker before you started vaping then you may want to start with higher content until you reach the very bottom. One can find e juice that contains zero nicotine which is the main objective of those individuals determined to have a nicotine-free life. Before you can do any of these you would need to find that particular site where you can find safe and authentic products