Just/only? What's the difference? Hi, Is there any difference between these words: Just /only. "I only want a tea" "I just want a tea" Thanks all you guys!

First notebook entry: Introducing myself Hi! I'm Lina. I'm 26. I live in a beautiful city called Medellín. It's located in Colombia. I work as an English teacher in a public university. Besides, I work as an assistant in the same university. I'm medium height, thin, and brunette. My eyes and hair are brown. I don't practice any sport. Most of time I'm working on my classes (planning, checking, e-mailing, etc), in my free time, I like meeting my friends, watching tv, or listening rock and pop music. I have many expectations here. I'd like to meet nice people and make new friends. See you around! Lina