How do I prepare form so user can tick more than one check box in a list?

"Yes when they convert to a form from Indesign they are assigned their own name in that process."

Yes, in InDesign you must rename all checkboxes one by one.

Creating checkboxes in Acrobat Pro is faster because they retain their name when copied and pasted, or when dragged with CTRL (Windows) or CMD (Mac).

Do you want to use checkboxes, a drop-down or a listbox?

You should start here: https://helpx.adobe.com/acrobat/using/pdf-forms-basics.html