Please name “All of the things I tried ….” so that we can avoid repeating what you may have already tried.
IIRC, LibreOffice has this feature and found the link below with search keywords “creating pdf forms linux”
Here is a how to with xournal (that Mark suggested in a different thread) + LO.
Although your question is PDF related, it is deviating from the OP’s query (thread) about a light weight PDF reader. In future, please start a new thread when the query is different.
— Arun Khan