My first English class in the university

Today ,I had  have my first English class in my university .My English teacher is nice but she said  speaks  English almost and I can't understand what does she say  said  sometimes .Umm ，on  the  one  hand ，I think my teacher teaches us in English all the time will help us learn more better ,haha …So ,I am also looking forward to my progress .
In    On  the other hand ,I found   find  many students in my class are very very good in   at  English .They can speak English flucently and they are  can  easy to understand English ,which   they makes   make  me feel stressful .
My English is so   too  poor ,especially speaking   spoken  English .How can I improve my English level ？