Well Coffee is fairly bitter. Its an aquired taste and most people like milk and sugar in it, which makes it taste better, but you have to get used to the taste. Some people even like it black, which means plain with nothing is it, but not everyone does. Id suggest putting milk and sugar in it if you want to drink it.
Tea is pretty nice though how it tastes depends on what kind. Regular black tea is a bit bitter but you can always put a bit of milk and or sweetener in it. I prefer tea without milk and a little sugar, but Ive had it with no sweetener and it's ok.