Are you doing some sort of work for your son for which he pays you via Venmo or is your son just giving you a "gift" every month to help you out?
Actually I would just enter your total income as Other self employment income or as Cash or General income. You don't need to get a 1099NEC or 1099Misc or 1099K. Even if you did you can enter all your income as Cash. Only the total goes to schedule C.
You can enter Self Employment Income into Online Deluxe or Premier but if you have any expenses you will have to upgrade to the Self Employed version or use any of the Desktop CD/Download programs.
How to enter income from Self Employment