A budget planner is a tool, such as a worksheet or template ... Your take-home pay, or your monthly income after taxes. A pay stub will likely be the easiest place to find this information.
These non-monthly pay periods can throw off your budget, which is why some people prefer paycheck budgeting (which sounds better than weekly or biweekly budgeting, despite the alliteration!).
If you stick with Google Sheets, the monthly budget template offers ... there’s a 34-day free trial. After that, you can pay $99/year ($8.25/month and $80 savings) or $14.99/month.