Assuming "it all starts in a tavern" or what have you, a first level wizard should be able to go and acquire what they need to get through enough encounters to buy a spell component pouch. The only big name 1st level wizard spell that's hard to get the supplies for in Generic Fantasy Hamlet #3567 is Color Spray, which requires three different colors of sand.

Just being dropped in the middle of nowhere with naught but your spellbook and the enemies bearing down upon you is something of another matter, though there are still a number of good spells that have relatively easy or non-existent material components (ex. Sleep, Benign Transposition, Nerveskitter, Charm Person/Hypnotism).

It's always worth asking your players about this sort of thing, but I think the wizard should be able to manage alright. He's probably better off than a Fighter who has to swing around a large stick while not wearing armor, though pretty much everyone is worse off than the Druid whose riding dog simply does not care and just needs to get hold of a divine focus for spellcasting.

It might be worth explaining what you mean by "almost no equipment," so we know what the wizard who presumably has a spellbook, a robe, and nothing else, is being compared to.