If you are writting it in past tense which I think you are, then these are some corrections :) I also tried to make the scentences flow better and sound more natural.

My day

Today is the weekend,I got up very late,
今天是周末，我起床很晚

I had my breakfast at lunch time,
我在午餐时间吃的早饭
Then I spoke English to my foreign friends all day
一整天都和我的外国朋友用英语聊天

I find speaking a foreign language is amazing just like magic.
我发现外国语像魔法一样有趣

I love it alot.
我非常喜欢它

But I'm not young ,I want to learn twenty words a day.
但是我现在不年轻，我想每天背诵二十个单词

The words I learned today will forgotten by tomorrow.
如果我今天记住了，我明天就会把这个单词又忘掉

I'm going crazy~
我快疯了