Today...

Today I got up early, I had a shower, I druank a coffee with milk and eate a banana for my breakfast and began thinking 'what I'am I going to cook for the lunch?' ,

mMeanwhile I'm going for a walk because today the .weather is good.

Today...

(Another way to say it...)

Today I got up early, I took a shower, I had coffee with milk and a banana for breakfast. I thought, "What am I going to cook for lunch?" Meanwhile, I went for a walk because today the weather was good.

(In the U.S. I think people usually say "took a shower" vs "had a shower". Also, you'll almost never here "the breakfast" or "the lunch/dinner" in American English. I always forget to use it in Spanish because we don't really use it for meals. I suggested verbs that were in the same tense to make it flow a little better. Those sure are beautiful flowers, no wonder you wanted to enjoy the day with a walk!) :)

Today...

Today I got up early, I had a shower, I drank a coffee with milk and ate a banana for my breakfast and thought of what I'm going to cook for the lunch , meanwhile I'm going for a walk because today the weather is good