Its absolutely awkward when you discover that there is no iron on your continent. Well, lets wait til we discover gunpowder.. and OF COURSE THERE'S NO SALPETER EITHER!! So you try to find an island where there are resources, but it takes a hell lot of time to have the new cities being more productive, you often have to build courthouses to reduce the production-corruption, and there after harbors to connect with your main continent. And OF COURSE THERE COMES ANOTHER CIV AND GRAB THAT RESOURCE BY BUILDING A CITY NEXT TO IT!! There for you have to make war with them, and when you arent able to build stronger units than Horsemen, archers and Longbowmen its almost impossible to make fair resistance so the only thing is just to quit the game
that is the definition of awkward
if i don't have iron or horses (rare), then i build archers and catapults. once you get to invention, longbowmen backed up with a couple of spears and 20 trebuchets will take a good few cities
if you have iron, you are fine. swordsmen, then medieval infantry and trebuchets will win you wars right through to the industrial age
if you have horses and no iron, then don't get saltpeter...
you either trade for it, or beeline to nationalism, get riflemen, and hold tight until artillery and infantry
however, it is possible to trade for iron. it's expensive, but entirely worth it
for example, sometimes i cannot make railroads after researching steam power because i don't have both resources. trades can eliminate the need for wars
handy if you're going a diplomatic, histographic, or cultural victory
if you get nothing at all within the first 50 turns or so, AND you're playing a crap civ (hittites, portugal etc) then sure, restart
it's not worth the effort