The Social Security benefits received plus the small amount of the other income will not be enough for you to be required to file a tax return.  None of your income is taxable so there is no need to file a tax return.  Unless you have had taxes withheld from the RMD then you should file for a tax refund.

 

Social Security Retirement/Disability/Survivors benefits becomes taxable when all your other income plus 1/2 your social security reaches:

Married Filing Jointly - $32,000
Single or Head of Household - $25,000
Married Filing Separately - 0

 

Standard deductions for 2018

Single - $12,000 add $1,600 if age 65 or older
Married Filing Separately - $12,000 add $1,300 if age 65 or older
Married Filing Jointly - $24,000 add $1,300 for each spouse age 65 or older
Head of Household - $18,000 add $1,600 if age 65 or older

 

long form

Starting in 2018 the forms have changed.  Under the new tax laws, there are no more simple Form 1040EZ or 1040A's.  Everything goes on a little Form 1040 that has six extra "schedules" with it, and if you need any of those schedules, you are not able to use the Free Edition.  

https://www.irs.gov/forms-pubs/about-form-1040 

Unless you had withholding from the RMD or you had health insurance thru the ACA you have no need or reason to file a return ... the interest/dividends that accumulate inside a retirement plan or IRA are NOT reported on an income tax return ... only the distribution is.