Reading can be hard especially if you are not used to a language. I know many of us are excited to learn English. English is new to some of us but it is interesting and soon we will all be good at it.
Sometimes reading makes us nervous especially if we find big words. This should not discourage you but instead make you a better reader. The same way you learn reading small words is the same way you will with bigger words.
Since practice makes perfect, reading is easier if done more often. If you are not be able to read some words try singing them out while playing. Read funny story books and start practising your reading especially when you are not in school.
If you did this, you will definitely become a better reader. Look out for picture stories too so that you understand the meaning of all the words.