It's been my experience that in FromSoft's games, the biggest challenges come from the smaller, nimbler enemies -- big bosses have attack cues that are easier to see, which makes it easier to learn when to dodge or block.

Elden Ring is my first FromSoft game, and yeah, it's been quite the experience so far. Also I get what you mean! When I tried to deal with kerberos (I think, that's what the gargoyle is called), which has vibes of "hurrdurr, first mini-boss in the first mini-dungeon", I realised that I am simply not used to enemies moving that quickly; even when I am able to see the signs of attack

My first was the Armored Core series, AC: For Answer specifically -- basically any other FromSoft game, but with giant robots instead of fantasy -- but the first one in the same RPG vein as Elden Ring was Bloodborne. If you want practice against both massive bosses and fast-moving foes, that game's a crash-course and a half, wrapped up in Gothic horror with distinct Lovecraftian undertones. (If you decide you're a fan of FromSoft's style of hard-but-fair difficulty, there's quite a few options for other games of theirs to try out after Elden Ring -- Bloodborne just happens to be my favorite of those.)

I am familiar with Bloodborne! :D It just happens that I never really dared/could afford the games until now. So I think for now I just want to get some overall experience in combat, be it the boss or not; and, preferably, not die to some surprise crabs, hahah.

Giant robots "souls" game sounds rather intriguing, though!

Surprise crabs are the worst. Not only do they pose a serious threat to life, limb and collected Runes, they make me crave seafood when I can't afford it.

There's some buzz going around that From's working on Armored Core 6 now that Elden Ring is out the door and pulling in profits and rave reviews alike -- I'm keeping my fingers firmly crossed, because no other game's quite managed to scratch the same itch as AC, and I want to get back into that series on current-gen consoles (the last entry in the series was during the PS3/X360 era of consoles).