When you type a tab at the start of a line, depending on your optional settings, you could either have added an actual tab character or set a first line indent on the paragraph. So we aren't sure which of these is the case with your document.

Try selecting and pressing Ctrl-E and then Ctrl-L. This will centre align and then left align the text. Changing to centre alignment will automatically strip out the leading tabs or spaces on the paragraphs.

The paragraphs should be spaced out by editing the style to apply a paragraph space before (or space after). It is poor practice to use two paragraph marks where one can suffice.

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Andrew Lockton
Chrysalis Design, Melbourne Australia