Sorry, there are things in both corrections. So, I'll write my own version:

Step by Step

Yesterday, I decided to do everything in my scope to improve my English, especially my writing and speaking skills. I've lost several (or 'many' that emphasize much more the sense of the sentence) job opportunities because my oral English is poor.

I know that I need to study every day. So I will post (something) every day.

Step by Step

Yesterday, I decided do everything in my scope to improve my English, especially my oral and written aspects. writting and spoken. On many ocassions, I lost several time a miss job opportunities because my oral spoken English is poor. I know that everyday I need to study it every day. So I will shall post an entry each every day a post.

Currently, I work in a center street in the central technical area for serving Brazil and Latin America. I have great experience in technical and management concepts of customer service. I majored in study engineering in systems and I have two children. I love going to the movies and read all kinds of books, that talk about usually on fantasy or fear but most preferably about on prophetic themes prophecies.

Your written English is not bad at all.  You just need to polish it and be more aware of its grammar conventions etc.

Step by Step

Yesterday, I decided do everything in my scope (power) to improve my English, especially writing and speaking. I have lost several job opportunitys because my oral english is poor.

I know that I need to study every day. So I will post every day.

Step by Step

Yesterday, I decided to do everything in my scope to improve my English, especially writting and speaking spoken. I lost several time many a job opportunity because my oral English is poor.

I know that I need to study every day. So I will post every day a post.

Step by Step

Yesterday, I decided to do everything in my scope to improve my English, especially writting and speaking spoken. I lost several time many a job opportunity because my oral English is poor.

I know that I need to study every day. So I will post every day a post.