There are a lot of "milk" options out there, and it can be very confusing! Oat milk, hemp milk, coconut milk, rice milk, hazelnut milk, almond milk, cashew milk...so many possibilities!
The first thing to keep in mind when choosing a milk alternative is nothing tastes like dairy milk except dairy milk! None of the options taste like "milk". They each have a different flavor, and some are suited to some things more than others. I personally haven't tried hemp milk or oat milk, so I can't comment on them. When we eliminated dairy milk from my son's diet, we switched to chocolate almond milk for drinking and for using on cereal. His preference before the switch was always chocolate milk, so I thought starting with a chocolate version of the non-dairy milk would be the easiest, and I chose almond milk because almond milk naturally has a higher fat content that rice milk, and therefore would hopefully have a better 'mouth feel' than the others. My son loves chocolate almond milk, and I think it's pretty good too (reminds me of rocky road ice cream).
Once I started cooking, I realized the need for keeping different milk alternatives in the house. I found that almond milk has a fairly strong taste, and it changes the taste of baked goods (yup...found that out the hard way!). For most baking and cooking, I use rice milk. If I'm looking for a slightly sweet flavor and a richer, creamier, buttery texture, I use coconut milk (which is an excellent source of medium chain fatty acids). For sauces (white sauce, gravies, etc.) I typically use a combination of rice milk and non-dairy creamer, either with or without broth.
Don't be afraid to buy small bottles of different types of milk and experiment with each of them in different ways, for different uses. Find out what works for you!