Oh right. Treat it like shooting a film camera (if you are familiar with it), other than the fact that the medium is different (digital) and you have the added benefit of different modern conveniences.
Learn how to read light - so don’t use auto ISO (just keep your ISO at a set number, just like it would be on film, so… 100, 200, 400, 800, etc. I would go no higher than 1600 (some occasions 2500 max) on the X-Pro 1 anyway. Learn how each ISO works in relation to the corresponding shutter speed + aperature combination. After a few goes you will start to learn how to read light and you will instinctively set your aperature and shutter speed to the correct combination even before you lift your camera to your eye.
On that note, while you can use Aperature Priority (whether with native or third party manual lenses), I would, again, treat it like using a film camera and set manual shutter speeds with the dial (so, not on A mode). This means that you are taking away the camera’s ability to think and calculate the shutter speed needed to give the exposure you want in your scene, and while you may think this is counter intuitive, I find the XPro-1 sometimes takes a bit longer to figure out what shutter speed it needs before it fires. So cut out the middle man and decide for it, that way you know your speeds are always exactly what you need them to be.
When street shooting learn how to zone focus (there are many tutorials on this). It really helps when you are adapting a vintage/film lens as it gives you a scale to better visualise what I am talking about. Essentially you are guessing the distance of your subject and you are making sure you are shooting at with a deep enough area of focus (f8 is your magic number) to compensate for any human error. This cuts out the camera needing to autofocus for you, i.e. you will not have instances where you think “dammit it, the camera focused on the wrong thing!” because you will have no one to blame but yourself.
And lastly of course, have your focus peaking on. Shame the colour cannot be changed, but this is kind of just the last layer in just confirming what you have is in focus. Although with some practice you will confidently know what is in focus depending on where your body is positioned to your subject and you will learn to slowly cut out second guessing yourself (which happens a lot in the beginning!)