If you’re going to use the chain whip you just made, you’ll also need a way to get that cassette off. A lockring remover is a must-have; unless you use one of the shady removal methods I’ve seen on the internet—which I wouldn’t necessarily recommend unless you don’t care much about the condition of the wheel after you use them. I recommend Park Tool’s iterations here that cost about $6, but you’ll need to buy the specific one for your brand/type of cassette. (By the way, I’m assuming you already have an adjustable wrench laying around somewhere to use with this tool. If you don’t, well, you’ll need one of those too.)
Over the years, I’ve come across plenty of articles that claim to tell you how to build up your cycling toolkit for cheap. Somehow the word “cheap” stops recurring in the long list of “essential” bike repair bits and pieces. The truth is, there is no real way to build a whole shop of tools all at once without plopping down a few hundred bucks. But in an attempt to show everyone that not all of us truly need a full complement of bike tools, I present the truest, most budget-conscious, and barest of bones options to you.

If you have just a short time in Seattle there is only one way to see the city. Walk at 2.5 miles an hour? I don't think so. Take buses and trams that you have to wait for and that might not even get you where you need to go? No way Jose. Drive your car? Hahahaha get outta here, don't even talk to me. But what about a BICYCLE??? Now that's the ticket.
Friction gear systems are a lot simpler to adjust, because the movement of the derailer cable can be modulated as you ride, every time you change the gear- they require less cycle maintenance. Modern index shifting systems are a little more complicated because each ‘click’ must release the exact right amount of cable to allow the derailer to move the correct distance to move the chain from one gear to another. Setting up and adjusting a derailer is not difficult and requires only basic tools, but there is a methodical procedure to follow.