What do you think is the difference between simple past tense and Present perfect? Sometimes,i dont know to use which.......

What should i do? I'm a Chinses girl,i'm shy.I want to make friends,but i don't know how to communicate with a foreinger ,so when we're talking,i would like to say something at will.I don't want to be rude, but i really don't know what to say.And after talking my friends may get angry so they wouldn't like to talk with me.What should i do?Should i stop making foreign friends？And if you are talking with a foreign people,what sentences will make you angry?

Do you think i should every grammar? First of all,i'm a journey student,we have a English test every month.I want to learn English well ,not only for the final exam,but also for my dream(i'm dream of traveling around the world).Do you think i should remeber all the grammar and all the vocabulabery(i don't konw how to spell it)(i can remeber every word all but it's too boring for me,i don't like it.)

Mother's birthday Tomorrow is my mother's birthday,but i have not bought gift for her.What is worser is that my mother want to hold a party but our revaltives don't want to do that.First,they think my mother will get too tired for making meals.Second,mabey,they have their own things to do.Oh, i don't know how to cheer my mother up

First notebook entry: Introducing myself Hi,I'm a journey student.My voculabery is poor (i hate referring to dictionary very much)and i'm a quite shy girl,so i don't know how to describe myself. To be honest,my English is poor,but i like it.I just want it to be better.My native language is Chinese,and i grow up in Tangshan.I enjoy listening to music,reading newspaper,playing computer games and so on.