If your husband qualified for Social Security retirement benefits -- whether or not he ever claimed those benefits -- or he was receiving Social Security disability benefits, when he dies
you can collect Social Security survivors benefits as early as age 60. If you wait until your full retirement age (66, for most people) to collect the survivor benefits, the benefit amount would be the same amount as your husband's full retirement benefits were (or would have been, if he did not collect them before his death). However, if you claim survivor's benefits between age 60 (when you first become eligible for them) and your full retirement age, the amount of your survivor benefits will be permanently reduced; the reduction is greater the earlier you claim the benefits. Also, if you claim survivors benefits before your full retirement age but continue to work, your benefits may be reduced if you earn over a certain amount of income during the year. There is no such earned income penalty once you reach your full retirement age.
If you are also eligible for your own Social Security retirement benefits, you cannot collect those retirement benefits and the survivors benefits. You may only collect one of those two types of benefits, whichever one is higher. Your local Social Security office can calculate for you which benefit is higher, and enroll you in that benefit.