Add or Subtract Days, Months, or Years current Date and month and year

how should I calculate current month to next months as per customer given For example
I have Date Field “Start Date” (01-01-2022)
I have Contract Period Filed Customer should give In this field 06 Months contract period so
That ending date automatically return should be like this (01-06-2022)

To find the first day of next month you could use CM+1D (where CM takes you to the last day of the current month and 1D takes you 1 day further).
To go to first day 6 months from now I would play around with +5M+CM+1D
That should get you close to what you need.
Hope it helps.