You give a $500 salary advance to employee ABC
Dr salary advance (balance sheet acct) $500
Cr cash $500
When it is time to be repaid, you withhold $500 in cash from ABC salary and reverse above entry
And you better get a signed receipt from ABC that states that ABC will repay you out of salary when you pay ABC the advance. Plus, you better have ABC get mgmt approval for advance or you’ll be creating advances all the time.
No need for journal entry for each employee but you MUST get acctg software to help you or better yet use a payroll service.