Simple Security
User Level Security
Access Security Seminar

ACCDE

Access Registration Seminar

You can also use SSE Installer for Access to build a professional looking installer.
https://www.ssesetup.com/access.html

It'd probably be better to sell your service than your database.  Different customers may need the software customized to their unique demands, and they'll ask you questions regularly.  So you'll need to have a way to charge them regularly.  If you get enough customers, their monthly payments may more than pay for your business.  So you may even give them the database for free, which will make your service even more attractive.  That was what happened in my old job.

thank you so much for your reply! very helpful, I appreciate it.

Ray thank you so much for your reply! very helpful, I appreciate it.

Kevin thank you so much for your reply! very helpful, I appreciate it.