Sandstorms tend to be played up in films and other media for the purposes of drama. In reality they're not quite as deadly as they seem. If your house is solid enough to resist the wind, You're best off simply staying inside. Sealing all openings into the house can greatly improve your comfort as well. It's a physical law^1 that sand can and will get into anything, up to and including hermetically sealed packages. Regardless of how good your weatherproofing is, you'll be spending some time dusting afterwards. Depending on the severity of the storm, structures are likely to have some degree of sand buildup. In modern Arizona and Saudi Arabia, most people will go outside with a hose or broom to get rid of the excess buildup.

People living in tents have much more to worry about. A badly staked tent won't last a single sandstorm. Proper weighting and staking is a necessary survival skill. Beyond that, tent placement is almost as important. A tent placed on the leeward side of a dune or hill will experience dramatically less wind than one placed on the windward side.

Food isn't a terrible issue in sandstorms, because the windblown sand is often quite dry. It gets everywhere and you may find your bread to have become slightly "crunchy", but it's not particularly concerning.

All of this is not to suggest that sandstorms are safe. A good friend of mine died in a sandstorm 3 days before Christmas when she hit a semi-truck. I've had personal injuries in the Altar desert when I was caught in one. Your best bet is always to be inside, out of the wind. Your hideout should be able to take the wind load without cracking. Beyond that, there's very little anyone can do. The sandstorm itself is rarely the most dangerous part of the storm. It's the lack of visibility, high winds and how other people handle the conditions that determine your safety.

^1 Note: Not actually a law.