My day

I leave the house and take out the rubbish at about 8:00. It usually takes me 10 minutes to walk to the train station. I have to change to another line on the way to work. I get to work at about 8:50, I usually buy some milk and bread in a market on the first floor before I go into the office.

I start to work at 9:00. I usually check my emails first while eating breakfast, but sometimes I am so busy that I have no time to eat.

I usually leave work after 7 pm. Even though I go straight home after work, I get home quite late . It is always be a long day.

I like cooking and I usually make dinner at home if I get back before 10 PM.

(1) There is a rule in English: One sentence, one idea. You can combine some of your sentences more logically into ideas with a theme.

It only takes me ten minutes to walk to the station, but I have to change lines on the way to work, so I do not get there until 8.50. On top of that, I usually stop to buy some milk and bread in a market on the first floor before I go into the office.

My day

I leave home and take out the rubbish at about 8:00. It usually takes me 10 minutes to walk to the train station and I need to change to another line on the way to work. I get to work at about 8:50, . I usually buy some milk and bread in at a market at on the first floor before I go into the office.

I start to work at 9:00 (this is fine, so these are only suggestions: you can also say "I start work at 9:00" or "Work starts at 9:00", if that is your workplace's start time....or "I start working at 9am", to convey when you as an individual start doing your work in the mornings),  . I usually check my emails first while eating breakfast,. B but sometimes I am very so busy that I have no time to eat.

I usually leave work after 7 pm. Even though I go straight home after work, I get home quite late . It is always be a long day.

I usually make dinner at home if I get home before 10 PM. I like cooking.

This is well-written. The only comment I have is that you should break up your sentences more using full stops. So, instead of making one sentence, break it up into two sentences where you can. I hope you enjoy your long day today. 

I leave home and take out the rubbish at about 8:00. It usually takes me 10 minutes to walk to the train station and I need to change to another line on the way to work. I get to work at about 8:50, I usually buy some milk and bread in a market at the first floor before I go into the office.

I start to work at 9:00, I usually check my emails first while eating breakfast. But sometimes I am very busy that I have no time to eat.

I usually leave work after 7 pm. Even though I go straight home after work, I get home quite late . It always be a long day.

I usually make dinner if I get home before 10 PM. I like cooking.