I think your writing is pretty good. I corrected some mistakes (see below). Well done, Fernanda!

So Last Sunday, I woke up very early to exercise. I am not so used at doing to waking this early, but since the day was a little bit cloudy, I decided it was an excellent idea. I think it is because here in Mexico the weather tends to be really hot, so I find that cloudy days are the best thing that can happen... really... so right after that I took a shower and i hurried on getting to get ready. On In the afternoon, I went to eat some supper at an amazing Italian restaurant. Right after that, I went for a coffee with my cousin and her best friend. It was a very relaxing day... Greetings!

Sunday

Greetings! Hey people! I will make a brief writing so I can practice my English. Please if somebody is so nice to correct, I would appreciate it...

Hummm... I will tell you about last Sunday.

So last Sunday I woke up very early to exercise. I am not used to doing this very early, but since the day was a little bit cloudy I decided it was an excellent idea. I think it is because here in Mexico the weather tends to be really hot, so I find that cloudy days is the best thing that can happen. Really! So right after I took a shower and I hurried on getting ready. In the afternoon I went to eat some supper at an amazing Italian restaurant and right after that I went for a coffee with my cousin and her best friend. It was a very relaxing day.