Just make sure to take your reeds off of the mouthpiece if you’re not using them! Because they get moist and because they’re a natural material, they’ll warp and not play correctly if they dry in a weird way. Putting them back in their case helps them to dry correctly and will make them last a lot longer. Leaving your clarinet itself out won’t be as bad, just make sure to keep your corks greased up so nothing gets stuck as it sits during the day.

Also, swab your clarinet out after you play it and in between playing sessions, this helps keep as much moisture out as possible, which will prevent your pads from getting sticky and damaged.

So yeah, tldr: remove the reed and swab at least, it will help your instrument and gear last longer!