Eating

I just had a bowl of noodles. My dad cooked it for me. It tasted bad but I ate most of it. After lunch, I felt sleepy, but I didn't want to sleep. Because if I sleep, the whole afternoon will just be gone*. I don't want to waste time so maybe this afternoon I will watch a movie, read a book or practice my English listening.

The word "practice" - this is correct (used as a verb) in American English, but if you want to write in UK, Australian or Canadian English, the verb is "practise" and the noun is "practice".

Or, "if I slept, the whole afternoon would just be gone". "If I sleep, the whole afternoon will just be gone" suggests that it is still the same afternoon at the time you are writing.

Great writing! Have fun with your afternoon! Do you go on YouTube for listening practice? I go on YouTube to find videos in Spanish (I am learning Spanish) and it is very good. 

Eating

I just have had a bowl of noodles. My dad cooked it for me. It tasted bad, but I ate most of it. After lunch, I felt sleepy.  But I didn't want to sleep, because if I slept, the whole afternoon would have just gone by. I don't want to waste time, so maybe this afternoon I will watch a movie, or read a book, or practice my English listening.

Eating

I just have had a bowl of noodles. My dad cooked it for me. It tasted bad, but I ate most of it. After lunch, I felt sleepy, but I didn't want to sleep, because if I sleep the whole afternoon goes by fast. I don't want to waste time so maybe this afternoon I will watch a movie or read a book or practice my English listening.

Eating

I have just had a bowl of noodles. My dad cooked them for me. It tasted bad, but I ate most of it. After lunch, I felt sleepy, but I didn't want to sleep, because if I slept, the whole afternoon would just be gone. I don't want to waste time, so maybe this afternoon I will watch a movie or read a book or practice my English listening.

(My dad cooked it for me is ok, but most people would say "cooked them," even though it's not grammatically correct haha.)
("so maybe this afternoon I will watch a movie or read a book or practice my English listening" - this is alright for casual writing/communication! Formally, you'd do "so maybe this afternoon, I will watch a movie, read a book, or practice my English listening")

Hope that helps!