I'm on my first actual playthrough and I'm in level four and one of my party got poisoned. Will I find a cure poison potion for them on that level or if they die, can I get them raised? Or should I just start over? I am concenred because I saved out of habit after fighting and was poisoned.

IIRC cure poison potions are likely present somewhere on that level, but you'll have to use them very sparingly. When there are monsters that can poison, there's potions to counter it.

If you can't find any, or used them all, you can resurrect party members on level 5, unless the party member is an elf. Elves remain permanently dead in old D&D rules. I guess their afterlife is just too damn sweet to give up.


Edit: After posting this I wanted to double-check something, and you -can- most likely resurrect elves on level 5, since one of the dead characters you find in the game is in fact an elf.
The spell Raise Dead does not resurrect elves, but whatever's present on level 5 (I'm avoiding spoilers) likely can, probably having access to the more powerful Resurrection spell.

Cast a slow poison spell and once you have left the spider area, you will have found a bunch of cure poison potions.