As a Muslim, if you are from the people of Riyadh or a resident in Riyadh, then you have to commit to the miqat of people of Riyadh . So, if you are traveling by air, you have to assume ihram from the plane and to formulate your intention when coming in parallel with the miqat.
However, if you did not succeed to know the miqat from the plane, then you can intend ihram when reaching the airport. After that you can go to the hotel to leave your baggage and resume the rituals of `Umrah. In the case you want to go to the hotel first, then you have to come back to the miqat for people of Riyadh where you can assume ihram and formulate your intention.