depends - id suggest taking short wars with the europeans if possible (watch for who they ally with etc) always if u can try to keep the biggest power under pressure or side with the smaller guys against the biggest euro and keep them all in balance.

You can aim to take the high value provinces in south america as war rewards (trade ports, those with modifiers that increase trade power etc) having a few of your own south american colony nations can help unless u want it all for yourself.

I usuaully try to grab all the coastline down to spartina and some of vinland. Avoid going inland to fast as it slows institution spread, but if u stick to the coast and have portugal onside early u can spread to your coastal provinces quicker and keep up with the technology. There are mission trees one u can focus on the americans and forget europe, the other is to get back to europe, the key is here as u start getting european territory setup exchariates and slowly expand them. They will be your puppets in europe. Grab any weak europeans u can a few playthrughs will eventually give u the idea. I dont think its possible to take over the world but u can focus on taking big development provinces, and once u start to steam roll if u play it smart u can usually grab a large chunk of the world.