Alfredo-  Your writing is perfectly understandable.  What I write below is how it might be said more typically (in the US..... mayb different in the UK).

Today was a normal day.  Get out of bed, take a bath, get dressed, eat breakfast, check email early and go to work.  But just before getting into my car, I noticed what would change the way I see the whole day: "A flat tire"

It takes about 5 minutes to change the flat tire with the spare tire; but a flat tire at almost 7 oclock makes you feel that you are going to have bad luck today (or "have a bad day").  Then you have three options; one is to ignore the event, the next is to get angry for everything that doesn't happen as you want (or "doesn't go your way"). The third is maybe the best option (even if you don't believe in bad luck). You pay more attention to every single thing in your day, and you try to compensate for your bad luck with caution and hard work.

When you start FLAT

Today was a common day. Get out of bet, bath, cloth, breakfast, early email check and go out to work. But just before aboard my car I noticed what changed the way would see the whole day: "A flat tire"

It takes about 5 minutes to change the flat one with the spare tire; but a flat tire at almost 7 oclock makes you feel that you are in a bad luck day. then one have three options, one is to ignore the event, the other is to get angry for each think that doesn't happens as you want. The third is maybe the best option (even if you don't believe in that bad luck). You put more attention to every single activity in your day, and you try to compensate your bad luck day with caution and hard work.

Happy bad luck day (^_~)

Keep working. You are doing fine.  -sven

When you start FLAT

Today was a usual day. I got out of bed, bathed, got dressed, and had breakfast.  Then I checked my email and went to work. But just before I got in my car, I noticed what changed the way that I would see the whole day: "A flat tire."

It takes about 5 minutes to change the flat tire with the spare tire; but a flat tire at almost 7am o'clock makes you feel like you are having an unlucky day. Then you have three options. One is to ignore the event; the other is to get angry for each thing that doesn't go your way. The third is maybe the best option (even if you don't believe in that bad luck). You put more attention to every single activity in your day, and you try to compensate your unlucky day with caution and hard work.

Happy Unlucky Day (^_~)

It seems like you are perhaps literally translating your native language into English.  The best advise that I can give you is to look up the use of the verb "to get."  It is a very trickly verb to translate because it can be used in so many ways, for example:

to get = to have

to get = to obtain

to get = to purchase

to = to accomplish

However, it is very useful to know because it is probably one of the few English verbs that you can get so many uses out of.

Also, remember to always use pronouns. You can't drop the pronouns in English like you can in Spanish, it will make it hard for you to be understood.

Lastly, your verb tenses should always be parellel.  For example:

I went shopping, practiced skating, and left the office. 

Never

I go shopping, went skating, and leave the office.