Hello and thank you for contacting the Toolset support.

To display each option in a line, you can use this, adapt it to your field's slug:
=========================================================================================
<p>
    [types field="my-checkboxes" separator="<br>"][/types]
</p>
=========================================================================================
Which will generate:
=========================================================================================
<p>
Option 1 <br>
Option 2 <br>
Option 3
</p>
=========================================================================================

You said that you want to display only the options that are selected, this is the default behavior. Are you getting some options that are not selected? If yes, please check what settings have you chosen for the field in Toolset->Custom fields. And make sure that the field will save "nothing" when an option is not selected instead of "0". Then save a post again to force it to remove 0s for the unchecked options and try again.

I hope this helps. Let me know if you have any questions.