My spouse died in this year

So there are two parts to this question -- 

 

First my spouse and I are both retired.   He was not at the age of RMD.  I inherited at IRA - BDA, as that was how it was set up by Fidelity.  How do I treat this?  Are there limits on the length I can hold the account?

 

Second, how will this affect my tax filing this year?