Okay, here I am to Hook you up...(pun intended).
Your stock OEM air filter and spark plugs are fine to leave in the bike until the bike hits 20K...up to 25K.
Given where you live, and that there is no extreme weather conditions, like super dusty, super cold, etc.....you are really okay to leave the air filter and spark plugs alone until that time....20K to 25K.
Then...at the exact same time (being facetious here) you can change the air filter and the spark plugs...and if you install a K&N air filter, and install NGK Iridium spark plugs......then...and only then....you can leave both of those items in the bike for a full 75K miles. (or 1 year, whichever comes first)
Okay, that was a joke, but you really can leave them in the bike for a full 75,000 miles. When you do remove the NGK Iridium spark plugs from the bike, that then have 75K miles on them, you will be surprised as to how well the plugs still look. But go ahead and put new ones in anyway...every 75,000 miles.
As for the K&N air filter....when you remove it with 75K miles on it, just clean it...recharge it with filter oil...and put it right back in the bike.
If you do both of these tasks every 75K miles, it is easy to remember.
BTW, when you do remove those OEM spaerk plugs that you bike came with, please tell us what plugs WERE in there, as I want to know.
Mine had the ND plugs in it, and I am not a fan of ND plugs. Despite what everyone else on the plant Earth may tell you, this bike runs much better with NGK Iridium spark plugs in it.