If you're talking about apps like Facebook or Instagram being forced onto your Samsung phone then I'm afraid you can't do much outside of rooting your phone, which has become increasingly difficult with Samsung locking most things behind Knox now. I'd look up a guide on how to do it and study it before going straight to it.
Yeah, Samsung phones are awful with their bloatware they force install, honestly one of the worst manufacturers I've seen in this aspect. Their devices include tons of useless garbage from Samsung themselves, as well as 3rd party apps force installed from their "partners" like Facebook and Microsoft. I recently went through my old Samsung phone and its truly outstanding, no idea how I ever used this thing. Their software just sucks. Its just horrible for so many reasons: privacy, security, storage space, performance, battery life, and overall usability and user experience are all hurt. No idea why they're like this and this desperate for extra money and a quick buck, despite most of their devices being flagships and not cheap in the slightest. Their hardware is pretty good in most aspects, so its just a huge shame.
Good thing is we can safely remove the BS through ADB on their devices, but we shouldn't have to at all, its ridiculous and its one of many reasons I don't recommend Samsung devices (Knox permanently tripping and bricking part of your phone if you root or install a custom ROM, and no bootloader unlocking on most devices at all being 2 other major reasons).
Just my 2 cents, I'm still using my unlocked S20 FE and have no such apps installed. Could most likely be from a carrier device and their subsidies of getting you the phone.
Good thought and that does happen too, but nope, my phone was unlocked, I don't buy and never have bought from carriers. You're just lucky, could be the region you're in or related to the model. This is a known and well documented issue and thing Samsung does, just see here and here.