Right my problem is that i want to do things like make segments of my text bold/italic/underlined or change the line spacing and so on but then i do this it does it do the whole document, for instance i want to change 1 line to bold i highlight it, change it then the whole document changes to bold If anyone could help i would be so happy

I would suggest using continuous line breaks. Go to the Page Layout tab and insert a continuous break before the unique formatting and also after. Then you can format the lines in between the breaks with their own styles. Hope that helps!