help with emerging

i am currently fixing a server and am curently on the 'entering new enviroment' chapter and have just typed the command 'emerge - ev world' and the server is coming up with

calculating world dependencies... done!

>>> emerging (1 of 157) sys-libs/zlib-1.2.3 to /

and then stops and doesnt do anything else
have i done something wrong?

Try running it with "p" or --pretend, to see if anything is blocking you from installing. Also, you might want to try an "emerge --sync" first to update your tree.