Awesome! Welcome to MFK.
Fishkeeping means water keeping, and that means regular water changes for most of us. Some people build systems that change the water all day, but that only works if you have a well (tap water is usually chlorinated and needs to be dechlorinated before use) or a large reservoir to drip from.
But not to worry, a 55g is pretty small and you could do well with a normal siphon and bucket arrangement. I change 50% of the water in most of my tanks every week and vacuum the gravel and scrape the glass all at the same time. Then I dunk my filter pads in one of the bucketfulls of old tank water before dumping it out and refilling the tank. I made a hose with parts from home depot so I fill my tanks from the faucet and add dechlorinator as they fill.
Just be sure your nitrates don't get too high and that your pH is stable and that's plenty of chemistry for an established tank with hardy fish. It's the first few weeks that will have your head spinning with ammonia tests and good questions we're here to help you answer.