You have established a training base in southern California, your horse has arrived at the destination all is well. Your horse will need a few days to adjust to the climate and change in hay.
Bathe and clip your horse and find the appropriate sheet/blanket/fly mask combination for the weather in the desert. We feed “Safe Choice”, a Purina product. It is an American based brand, but was difficult to find locally. Once the jumpers were competing at Thermal, the brand was brought in. Don’t assume that you can find the same brands of horse feed here as at home. Make sure you contact the local feed store to find if they will bring in a supply of any specialty feed you may require.
Ask about all the barn and arena rules. These may be different than at your home barn. Be polite and respectful and always clean up after yourself and your horse. You are a guest boarder and remember you would like to be welcomed back. Other riders are a great source of information on where to find tack shops, boot repair, veterinary advice, farriers, showing etc.
Personal accomodation becomes a matter of choice. I have an RV, and as long as there is a place to park near the barn, I am home. There are condos, hotel resorts (suites) or rental units available locally.
Now that you and your horse have arrived safely and settled in, it’s time to start riding.