I am playing a sorcerer (lvl 85) on ladder 3 and sorcerer (lvl 28) offline.
I can say this for sure Diablo 2 Resurrected is by far the hardest game I have played in a very long time once you enter Hell difficulty. In case you didn’t know there are 3 difficulties to complete the Acts 1-5 in, normal, nightmare, hell. Unlike other games each mode does more than just make enemies tougher, you get more good stuff, the maps get bigger in hell, resistances change via a modifier, enemies have immunities like cold making my blizzard useless.
The immunities part stopped me in my tracks when I hit hell in a blizzard sorcerer, I had to change my spec to a hybrid meteorb spec that I absolutely have grown to hate, it’s just an annoying spec with a slow but powerful meteor and frozen orb that is a bit weaker. It does however do the job but progressing is extremely slow, each mob has to be kited to just grab a few so not to overwhelm my mercenary. The mercenary dies all the time and cost 50k gold to resurrect, btw I’m low on gold all the time.= doh. I have a handful of starter runewards but some of my other pieces of gear really need upgrading, for instance my blue magic necklace just has +23 resistances and no other stats due to needing resistances so bad making me a bit weaker without more stuff on it.
Anyway I started playing another sorcerer in offline mode which has an advantage of allowing you to set /players1-8, this raises the monster difficulty a bit allowing more loot and xp, then a setting of -enablerespec in battlenet app allows you to respec your build however many times you want by pressing alt and clicking on your strength attribute point button in character screen. I would now suggest playing this game to start using offline mode, this way you can experiment more with builds learning which one works best for you. You lose the ability to group up and get help though which can slow you down for those harder challenges.

I made it to Diablo solo then I was so annoyed at how slow my progress was I made a group game and some big timers helped me all the way to Baal, then dclone spawned and I made a public game asking for help so I could get the anni charm one of the most powerful pieces of gear in the game. I couldn’t hurt Diablo Clone as a level 84 with meteorb build before running out of potions and my merc died all the time. My first anni was 1,11,15,6 these are four lines of stats and not super good but they do help a bunch still max is 1,20,20,10 so I will try killing the dclone with help again until I can kill the uber 110 level guy myself.
The screenshot below shows one of my shared stash tabs filled with runes, most of my runes are low, I have a couple mid runes at max. On the right is my inventory stash, in d2r you fill your inventory up with various sized charms all having various stats to help you survive hell mode, your bag looks like this in hell mode. On normal you have a ton of potions, nightmare a mix of stuff. Yea you have no real space to pickup lots of loot to sell easily, so you have to find ways of nit picking when on the move for just special pieces then putting in the cube shown on lower right, this has a bit more space inside it. You can see my very first ever Annihilus charm being hovered over to see stats., a note the Anni really buffed me all around especially the +attributes now I really want a better one.

I wanted to get terror zones unlocked on hell mode to level up solo more and help getting the way better gear drops, d2r is the most exciting game for gear drops due to the rarity of some pieces and the expensive runes. I was watching a streamer who has played for 20+ years and a staff dropped with +5 skills and he got all excited saying it was the first time seeing it in all those years, that’s just crazy how much gear is in the game. Now I am able to level a bit quicker and due to my using all 3 of my respecs up I need to farm 4 essences to make a token that allows me to go back to blizzard spec once I have a sunder charm or more -resistances on enemies options.
This game really is one of the best games I have played, people will help you out a ton if needed. It’s a bit tricky to figure things out, many of the players have been playing it for 20+ years and new games are not exciting to them which I too am feeling.