Never wash it, never dry clean it. Both strip the wax that makes the jacket weatherproof, and there's no gentle version — a waxed jacket that's been through a machine is a ruined one. This is the rule that matters most.
Clean it cold and by hand. Sponge mud and marks off with cold water and, at most, a drop of mild soap on a stubborn spot. Then hang it somewhere airy to dry. Scuffs and creases that show pale are just the wax moving — they're part of how the jacket ages, not damage.
Re-wax about once a year. When the fabric looks dry and matte, or water stops beading, it's time. Warm the tin of wax so it goes runny, work it into the cloth with a cloth or sponge — paying attention to seams, cuffs and shoulders where it wears thinnest — then warm the whole jacket with a hair dryer to melt the wax in evenly and let it cure overnight.
The waxed canvas bag follows the jacket. The backpack's waxed cotton wants exactly the same treatment — sponge it cold, never machine wash it, and re-wax the panels when they look dry and stop shedding water, paying extra attention to the base and the seams that take the most wear. Air it out and empty it after a wet day, and treat the leather trim separately with a light conditioner.
Store it cool and hung. Keep it on a broad hanger somewhere ventilated, never folded away warm and damp, and never sealed in plastic — waxed cotton needs to breathe or it can go tacky and smell.