If it's a permanent life insurance policy that builds cash value inside the policy, you may be able to borrow from it. If it is a term life insurance policy, there would be no cash value inside the policy, so no loan is available.
The amount you can borrow depends on how much cash value has accrued inside your life insurance policy. Some life insurance carriers allow you to borrow up to 80% of the cash value in your policy.
When you borrow money from your life insurance policy, you're creating a loan as the money is expected to be paid back and loans require interest to be paid on the loan. So, basically, you are paying yourself back the money from your policy.
If the insured dies and there is an outstanding loan balance on a life insurance policy the insured owned, the beneficiary of the policy would receive the death benefit less the loan amount and any interest due on the loan.