Retirement tax questions

Still looking for clarification:  

Since I currently have a 2019 1099-R, box 1 with $800, Box 2a $0.00,  Box 2b unchecked, Box 7 PJ.  This was due to maxing out 2018 Roth at $5,500 earlier in 2018, and having made too much at the end of 2018, where I had to get a portion refunded.  

Question 1:  Am I required to Amend 2018 taxes.  Note:  It appears in reviewing 2018 taxes "IRA Contrib Wks" the amount has already been subtracted.  

Question 2:  I do not see a line 15b on 1040 (2018); only line 15.  

Question 3: Do I need to do anything to my 2018 taxes (amend), since 2019 1099-R, line 2a is $0.00.