How to use Join for two tables that have related data but in different column names
You have to specifically list the columns you are interested in, rather than simply stating *

The first table can remain like this:
SELECT PROJECT_FORM.*, …
then you list the columns you require from the other table one by one.

SELECT PROJECT_FORM.*, ASSIGNMENT.HSID
FROM PROJECT_FORM
JOIN ASSIGNMENT ON PROJECT_FORM.FORMID=ASSIGNMENT.FORMID