Everyone is going to tell you that you MUST get the Apple Magic Keyboard and Apple Pencil. I'm going to tell you to save your money and get a "used-like new" Logitech Slim Folio Pro keyboard case (you can find them for a little as $20 on Amazon). Look specifically for the model made for the iPad Pro 1st gen (2018) as that has the same camera bump as the Air 5. The keyboard is excellent and the case offers pretty decent protection. No trackpad, but you've got the touch screen or a stylus (or even a mouse).

For a stylus, you can find a decent non-Apple Pencil knockoff for $25-$40. Some even have wireless magnetic charging, just like the Apple Pencil. I've got a Penoval A4 that I quite like. However, if I was to buy something today I'd definitely get a stylus with magnetic charging (a feature I did not find a year ago).

I'd also suggest a regular folio case for times when you don't need your iPad in a keyboard case (ie. reading, note taking, etc.). ESR makes an excellent magnetic folio for around $20 that is just like the Apple version for $70.

Finally, I'd consider getting a more powerful charger than the Apple charger that came with your iPad. Especially if you might need to re-charge while you are out and about. Your iPad can charge at up to 33W, but the provided Apple charger is only 18W. You can get an inexpensive 45W charger that will let you re-charge your iPad nearly twice as quickly. If you get a second USB-C charging cable (a good idea so you can leave one at home and take the second cable in your everyday carry bag) be sure to get a cable that is rated for at least 60W from a reputable brand (like Anker). There are a lot of cheap cables out there that claim to be "high speed charging" but don't deliver anything more than about 12W.