Corrections in red.  Stylistics and comments in blue.

Exercise. Ten conditional sentences: 

I will not be late for work if I do not miss my train.  [1]
I will repair my flat very soon if it is not very expensive.  [2] 
If I see that it's rainy when I'm going to go out, I will take my umbrella.
I will go to a river rafting in a cataraft with my family in two weeks if all goes as planned.  [3]

If I worked for an airline company, I could fly by plane for free.
It would be better for me if I went to sleep not so late.  [4]
I would use a bicycle sometimes, if I had one.

If I had passed the exam in driver school sooner, I would have had a driver license.
I wouldn't have thrown out the vegetables if I had eaten them in time.  [eat   ate   eaten]
If I had memorized more English dialogs, I would have spoken English much better.

[1]  Be consistent in your use of contractions in the same sentence.  Either:  "I will not... I do not", or "I won't.... I don't."

[2]  I assumed by "flat" you mean "квартира", you could say, "I will repair my flat very soon if it is not very expense."  However, a "flat" also means a flat tire, so without context I wasn't 100% sure what you are going to repair!

[3]  A catamaran is not a raft.  However, a "cataraft" is!

[4]  A more common way of expressing the same thought is, "It would be better for me if I didn't go to sleep so late."