" Can I reserve the airport shuttle" ? or " a seat on the airport shuttle" ?

" 我可以预订机场班车吗？" 或是" 可以预订一个机场班车的座位吗？"

What time does the airport shuttle depart?

机场穿梭巴士几点出发？

What time does the airport shuttle depart?

机场穿梭巴士几点出发？

So first ask: " Do you have an airport shuttle" ?

" 你们有机场班车服务吗？"

From the airport to the city, you can catch the airline bus or take an airport shuttle.

从机场到市区，你可以乘坐机场大巴或机场班车。

In that case, you could also take airport shuttle or train.

在这种情况下，您也可以乘坐机场班车或火车。