If you forgot the passcode for your iPhone, iPad, or iPod touch, or your device is disabled

If you have two different connectors, you are going to have to get an adapter. I'm guessing that you have a newer MacBook Air with the USB-C, and the iPad uses the lightning? If the Apple Store is a ways away, try something like Wal-Mart, Staples, Target, Best Buy, they all sell Apple power connectors. You need this one, https://www.apple.com/shop/product/MX0K2AM/A/usb-c-to-lightning-cable-1-m?fnode=97&fs=f%3Dcable%26fh%3D458e%252B45c4 This is from the Apple website, but you should find it at one of the stores I indicated. Then follow the steps here, If you forgot the passcode for your iPhone, iPad, or iPod touch, or your device is disabled - Apple Support

You also mention parent passcode. If you have forgotten that as well, you will have to set the iPad up as new, not from a backup, as the backup contains that screen time passcode and will put it right back on.

There isn't an option other than connecting to a computer. It doesn't have to be a Mac computer so if you know someone who has a Windows computer you could use that. See the following from If you forgot the passcode for your iPhone, iPad, or iPod touch, or your device is disabled - Apple Support

You need a computer to follow these steps. If you don't have a computer, borrow one from a friend, or go to an Apple Retail Store or Apple Authorized Service Provider.

It sounds like your Mac is one of the newer models that only has USB-C connections. If so, the other option would be to buy an adapter: USB-C to USB Adapter - Apple

You can order that online from Apple with free shipping.

I’m afraid a computer is needed. Perhaps you have a friend or neighbor whose computer you can use? Or if your work allows it to take it into work, install iTunes and use that?