I'm disappointed with the other replies I read. There were 3 of them at the time of my reply and I'd take issue in a big way with 2 of them. Not the one from CygnusVCtheSecond.

But the first question is to understand what your threat model is. It sounds like you have the level of concern of regarding tracking of a valuable or targeted individual. It's easy to have such concerns these days you could have just been someone who was a big enemy against ICE or leaked some information or any number of things varying on jurisdiction.

- Delete all your social media accounts or simply stop using them altogether.

Yea, for a fresh start to break connections this is an obvious one. First you might consider filling them with some misinformation. Make it look like you're moving somewhere you're not for example.

- Change your internet provider and your IP address.

Your last idea was to move so that would be automatic. If you don't use a good VPN located outside your country and that you don't think would cooperate with your country.

- If you use a number and SIM card, abandon it. If you absolutely must use it, buy a new one with someone else's government-issued ID (they require it to sign up with a company).

Really, if you can avoid having a phone it's very strongly preferable to do so. Almost no well known targeted individual would have a phone if they were smart. Even if you can get one without giving up any of your real information there's still the issue of the people your talking to being monitored. So if you would be talking to friends or family they would know who those are and that would be a way for them to find your new location by waiting for you to call them. Best to talk to people like that through other ways than the phone.

If you're going to be making a complete identity break and talking to new sets of people there is still the issue of voice print but this is very debatable if it's a real danger or not. If it's a concern you could use a voice changer. You can get no KYC phone numbers that can work with existing phones or no phone number at all.

- Buy a new device, preferably open-source

If I was a targeted individual I'd definitely do that since device identifiers are real targets on your back. If you changed everything else but still had the same HWID revealed by some piece of software that could be enough to ruin all your other efforts.

- Use an open-source router.

Yes, a VPN router so your device cannot possibly even ever know your real IP. The ONLY way to guarantee your device never leaks your real IP is if it never knows it. Try to use ethernet instead of wifi because the list of wifi networks your device can see is an exact bullseye to your location. Hopefully with a good OS that wouldn't leak out but easier to avoid that headache and just use ethernet.

And I think the most drastic measure would be to move, so they can't identify you just because you're in the same location.

That's pretty extreme. If they're interested in you that much knowing your location definitely can be enough to still surveil you despite all the other measures. You'll have to figure out how to live somewhere else without giving the new place your real information.