If you're stepping away for a while, you don't have to cancel. On a monthly plan you can take a month off, and the offer sits inside the cancel flow, so that's where you start.
Go to Settings → Plan & billing and choose Cancel plan.
On Before you go, pick I'm not using it enough and choose Continue. That's the reason that brings up the pause.
On Pause instead?, choose Pause for a month.
Nothing changes straight away. You keep what you've paid for until the end of your current billing period, including your monthly usage, and the pause starts on that date. The billing page shows when your plan pauses and when it starts again. Change your mind before then and choose Keep my plan: nothing changes, and your plan renews as normal. Nothing is charged when you schedule a pause or when you keep your plan.
While the pause is on, there's no monthly usage and no plan features. Your Series don't post, nothing publishes, and you can't change plans. If you have usage packs, you can still make and download videos with them. Nothing is deleted: your Library, your Series and your settings are all where you left them.
After the month, the plan comes back on by itself and billing starts again. To come back sooner, choose Resume plan at Settings → Plan & billing. Resuming charges your plan's monthly price that day, then starts a new month with fresh monthly usage, and the confirmation shows the amount before you pay. If the charge doesn't go through, nothing is charged and the plan stays paused until you update your payment method and resume again.
Pause is only offered on an active monthly plan. If a month off isn't enough, Cancelling your plan covers what ends and what stays.