Milk, the stuff in the cartons, was the very first thing I quit drinking. Even before I became vegetarian.
Mostly because I became so aware of the abuse of dairy cows. but also because it was so easy. Just buy some soy milk.
I think at first I didn't like the taste of soy milk. but that didn't bother me. I rarely drank it straight. Once you put it on cereal or use it to make oatmeal, or make it into a smoothie, you can't really taste it at all. But now I don't mind the taste of it at all. In fact, I prefer it over regular cow's milk. So I think its just a "taste thing". You get used to it.
There are lots of brands of at the market, so I would recommend you try all of them. they do taste a little different. Also, they have different flavors. I usually buy "light vanilla". I think it tastes good enough to drink straight. and it's just sweet enough so that I don't have to add any sweetener to my oatmeal. If you buy some and don't like it - i bet you can use it for smoothies. Add Peanut butter and chocolate - it will taste pretty good.
The big reason I stick with soymilk is the protein. It has way more than most of the other plant milks.
Right now almond milk is the most popular. And it seems like everyone loves cashew milk. the new kid on the block is Pea Milk. it's very nutritious.
As far as health and environmental issues go - every plant milk beats the heck out of cow's milk.
You may have heard some bad stuff about soy but all of it is made up by the dairy industry or the Weston A Price Foundation. Soy is very healthy. As far as environmental issues go. Soy uses a lot less water than the nut milks. but they all use less water than dairy.
Oh, and when buying soymilk look for organic soy milk. Farmers who grow non-organic soy use GMO seed, and the beans are swimming in herbicides.