If you have any liability then buy life insurance. If not enjoy life!, no need to buy.
There are various methods to calculate your life insurance need - Human Life Value (HLV) or 10 Times of your annual income or buying life cover for home loan or covering specific risk. So check these methods and calculate your sum insured.
If you buy two different policies from different insurers, each will pay in case of claim.2- If I take multiple Term Insurance (from different companies), can a claim be made to all of them.
It always good to over insure yourself than under insure.