Is it permissible for me to use the money my employer gave me to buy clothes for other matters, such as lending it to a friend or paying for driving school fees, knowing that I bought some clothes he hasn't seen before and the amount paid does not cover these expenses, but rather I took another advance for the license?

If the company owner gives money to an employee to buy clothes suitable for work, it is not permissible to spend it on anything else, based on the Prophet's (peace be upon him) saying: "Muslims are bound by their conditions in what is lawful." However, if the amount is an aid to provide clothing, and the employee already has enough suitable clothes, then he is permitted to dispose of what exceeds his need.