Yea! If in doubt, unplug every other drive. It’s a good practice.

going with the ‘something else’ option is the option you wanna do if you have something special in mind. It kinda requires that you know what you are doing. It’s not that hard to learn. But you might need a little patience to read up on to get confidence. Since you have an entire drive for the purpose, having the wizard do it for you is just easier. The windows installer have similar options.