Usually it's "too + adjective" when it's a negative situation: It's too cold. I'm not going outside. It's too expensive. I'm not going to buy it. Her lecture is too fast. I can't understand it. Sometimes people use it informally to mean "very very". If your friend tells a funny story about what happened to him, you might say "That's too funny." You mean you really think it's funny. Nothing negative about it. "She's too beautiful" could be like that, almost in a joking way, like "She's soooo beautiful" Or it could be something like "She's too beautiful to ever consider going out on a date with me." You can't use "too + adjective" to mean "very" or "a lot of that quality". The soup is very spicy. I like it like this. The soup is too spicy. I can't eat it. The car is very expensive, but I think I can afford it. The car is too expensive, so I have to look for a cheaper on. My country is very beautiful. (not too)

When we use "too [adjective]", we mean there is some kind of a problem, or that something is unsuitable. eg. "It's too hard." = It's so difficult that I can't succeed. Using "too" in positive situations is very rare, but your example of "she is too beautiful" can imply that there is ugliness or nastiness about. "She is too beautiful for someone as ugly as you" or "She is too beautiful for the other women - they are extremely jealous." In general, you don't use modifiers like "too" for strong adjectives.

thank u so much.

Both ok. Too + adj is usually negative thing although using it with a positive adj like beautiful can work, especially in informal speech. She is too beautiful, I can't stop thinking about her.