Okay, without knowing what exactly the problem is, I'll do my best.
The easiest way to do this is to use the createspace templates for the trim size you want.
Make sure that you are NOT using tabs etc as they will look weird on the template, follow the steps below.
1. download and open the CS template for the trim size you want. It automatically opens in word - it's easier to use the already formatted one and just paste in your text.
2. open your MS in another document.
3. One your MS - select all
4. clear / remove all formating and styles - this will remove all the tabs etc.
5. in the 'paragraph' tab there is a section for 'indentation' in teh drop down for 'special' select first line, then in the 'by' drop down select the right indent - bear in mind that the trim size is smaller and the indent in in cm, so you will need to reduce it by about half.
6. Start to copy your text by highlighting it one chapter at a time and pasting it into the correct section - sometimes word does weird spacing here, but here's how to fix:
7. in the template highlight all of the text you just pasted in, go back to the 'paragraph' tab and this time you want to go to the 'spacing' section at the bottom, make sure you select '0' in the drop down menu for 'before' and 'after' - this will remove the weird space between the paragraphs.
this should solve all the weird things that word pdf's do.