Get a Pine64 or Rock64(Pro) ARM SBC and install OpenBSD on it. I guarantee this will confuse any of the plebs employed by your government. ^_^
Unfortunately those boards are manufactured in and ship from China, so the shipping times might be kinda long these days. You can try other boards, but really that's the best supported one in OpenBSD. RPI3 is supported but the hardware is kinda crap, so I don't recommend it. There are other boards too, with various levels of support. I have pic (made in Bulgaria), which works fine except there's no video driver, so I can only use it over ssh or serial connection (which I do from an older 32-bit ARM SBC that runs a customized Armbian Linux). The funny thing is their Teres laptop uses the exact same A64 SoC, but that one does have working video in OpenBSD, probably because it uses the equivalent to my board's LCD_CON1 rather than the HDMI port. But anyway that's an interesting idea if you're looking for a small, low-power laptop.
Otherwise, just look at other unusual hardware and OS that normies don't use. That means definitely nothing with x86 hardware or any version of Windows or Mac OS. And even if you go the Linux route, try to pick one of the more niche ones, like Gentoo, Slackware, or Alpine. And avoid SystemD also, because it was designed to unify Linux, and you want to be different in order to make life harder for goons.
So anyway that'll keep the cops and other cianiggers off your computer. For the rest (network traffic), you have to use Tor, I2P, and such. That's not my expertise tbh, so I won't say more about it.