Definitely start out with a
broad selection of different flavors. Unlike some of my fellow veterans commenting here, I would
not downplay the tobacco flavors ... and there are all kinds of variation on the tobacco theme (RY4 is only one of them). Many of us prefer one or more of those over the non-tobaccos. I think that some type of "Marlboro" (however it is misspelled) or "USA Mix" is a good base line. [If you have been a menthol smoker, of course include at least one of those.]
Certainly sample some of the fruits, candies, and beverages. [As a primarily tobacco man, I also enjoy a good strong coffee flavor ... and chocolate mint makes a great change of pace.] You'll find out quickly enough whether you are a tobacco man or a sweet-tooth man ... or a bit of both.
Small bottles are a cost-effective way to do such sampling.
This article lists some of the juice sampler packs and small bottles available. For example: that Vapor Station package is an intriguing, cost-effective one ... NHaler has some great-tasting juices in 6-ml bottles ... Cignot is a great source for 5-ml bottles of China-made (Boge) e-liquid.
Bear in mind that China-made (e.g., DeKang or Boge) e-liquid is virtually the same from supplier to supplier, but USA (and UK) -made is unique to each supplier (in most cases). So if you don't like USA-made menthol from one supplier, you might love it from another.
Enjoy the adventure!