Our MacBook Air will not turn on. We tried holding power button for ten seconds and a couple of other measures read online. Machine is only two years. No shop open now, are there any other solutions?

If your Mac doesn't turn on - Apple Support is the definitive resource. There is no harm in performing those steps repeatedly until you give up. Try other power adapters if you have them. Try other cables. Try it with power connected, without power... etc.

If yours is an Intel Mac, try an SMC Reset: How to reset the SMC of your Mac - Apple Support. That doesn't apply to newer Macs with Apple Silicon.