I successfully added my business logo on sales quote and sales invoice forms. However, it is positioned rather awkwardly on a random position (my forms are also themed), right side below top colour theme. I wanted it on top left or top right. Is there any way of re-positioning the logo?
You have to edit the theme.
I am not really sure what you meant by the above statement, but the logo set under Settings would appear on all your documents unless you have hard-coded the logo to your theme.
you may want to read the guide https://www.manager.io/guides/9834
all the default themes available in Manager shows the logo on top-left or top-right.
if you are using a custom theme, then it is your responsibility.
No positioning of any element in a theme is random. They will appear in the same position where the theme code places them every time. When that code is your custom theme code, they are appearing where you put them.