start date in H2 my renewal column is automatically given a date 12/01/1901

I have a spread sheet

A column is - Last Name

G2 column is - DATE COMPLETED
They input the date the completed the course

H2 Column is - EXPIRES IN
This is set to give me the date 2 years from DATE COMPLETED

I2 Column is - Days until I need to renew

J2 Column is - STATUS

Problem : If I don't enter a start date in H2 my renewal column is automatically given a date 12/01/1901 as an expiration date, which in turn makes I2 a negative number -40043, and makes the STATUS past due

What I would like do is if there is no date entered in date completed(G2) then Expires in (h2) is left blank along with DAYS REMAINING (I2) and STATUS(J2) could show idk NA. Its seems simple and I have tried hard, but I am at my end and in over my head. Any help would be appreciated.