Moving input jacks is not a problem as long as you have room to do so and plan it out. It's worth noting that every PedalPCB has top-mounted jacks (I'm pretty sure that's universal for PedalPCB). All you need to do is give yourself enough lead room on the wires to put the jacks wherever you want. Additionally, it is possible to add expression jacks depending on what you want to do and what mods you're able to dig up. I would recommend if you're new to building pedals is to just start with simple boards and following them to the letter until you get real comfortable with building, soldering, troubleshooting, and reading schematics. I started building early in quarantine last year and I'm only now really starting to get the hang of things it feels like. In terms of easy first builds that are very simple to recognize whether they are working or not, I'd recommend the Ionizer, Amentum, or Je T'aime. I'm sure others could let you know of other simple first builds.