That depends on the type of life insurance plan you choose to purchase.
Usually, permanent life insurance has guaranteed level rates for your entire lifetime. So, your premium would not increase in the future.
However, a level premium term life insurance policy has level rates that remain the same each year for the entire duration of your term life policy.
Level term insurance offers level rates for a period of 10, 15, 20 or 30 years, usually.
If you choose to renew a term life policy, your rate would increase at the time you renew your policy for an additional term, and the new rate would be based on your age at the time of renewal.
Learn more about when do life insurance rates go up?