Nanny Pay, tax, other expenses

Hello all, due to covid our child-care situation has changes and now we are scrambling to look for new care. I’m wondering how pay works for nannies.

So far I have found I will need to consider Medicare, SS, unemployment insurance (both federal and state), Workers comp and sick time (possibly PTO). Additionally, we will need gas reimbursement if/when they need to commute our kids.

We are looking for part time work (12-18hrs/week)

So how does this work? If we pay $XX/hour is this post all those expenses? I ask because most of the blogs talk about those as after expenses. however, all jobs I have had have deducted Medicare and SS form my check. Sick time being lumped with PTO. Workers comp and unemployment was the only one i figured would be paid separately.

Also I read Federal and State taxes don’t need to be withheld. is this right?

For parents out there - do you manage your own account? ($500-$700/year is a lot for a company so I’m hoping i can get some advise for DIY)
Do you have a bank account/saving account dedicated to this?

Am I forgetting anything to consider?