Really depends. My mileage covers my ride share taxes. But I also have a herd of children/dependents and other deductibles. I would certainly stash some coin to be safe, and if you end up not needing it you now have a savings for auto repairs.
Yes, you'll have to pay social security either way. So I'd set aside at least 10%.
In my two years, I've never had to pay income tax. The $0.56 per mile tax deduction has more than offset my fares.
I do destination mode to the airport in the morning, then turn off UberX and do only Select during my drive from the airport to work, then Select back home. Rarely get rides on Select of course but it has the dual advantage of only getting occasional higher paying Select rides as well as stacking that mileage up.
I’m an ex irs person who drove 887 trips around 10k in mileage. Just remember ordinary and necessary for your industry. Phone, yup, apple rents them you know. Phone plan, yup. Car washes, yup. 10,000 x .54= 5400. I had a nice small loss, which can offset the income from my real job. Just remember your mileage logs must exist!!