Formula help required

Could somebody please give me some guidance on creating a formula please.
What I am trying to achieve is to push a date by a number a weeks. The first column contains the date, the second column contains the number based on weeks, the third column is where i require the new date based on the previous two columns.
First column = 01/01/2022
Second column = 3 (number of weeks)
Third column = 22/01/2022
Can this be achieved? I have tried ADD_DAYS to ensure that works, although when a item is blank it will show some random date in the third column. If zero is entered it will mirror the date in the first column. Ideally if the second column is blank I would like the third column to be blank. I then tried ADD_WEEKS but that came back as unrecognized. So I presume this is not a function.