Yea, not bad for start so I'll rate it to motivate you.

Thank you little Aleksa, my son..

Nice far background!
Recycled official constructions used in sensible proportions. I want to see more of that, but with original content.
Tips:

• Objects are a must-have. Empty flat areas are a no-go.
  
• Find a good ratio between horizontal and vertical play (individually for each map).
  
• Not too much open air (unless intended / design decision / concept). Keep line of sight in mind for gunplay.
  
• Think what you would do as a player when making the layout.
  

Please make sure your screenshot URL ends with ".png" or ".jpg" so the preview shows correctly. I've fixed the entry this time around but next time I'll just delete it.

Cheers.