Does job creation in the US affect the world or is it beneficial for just the country itself?

Job creation in the USA will have a positive affect on jobs elsewhere in the world since the USA trades with virtually all other nations in the world; and trade creates wealth for all parties to the trade. Trade within the USA creates wealth for all parties within the USA; and some of the wealth created will eventually result in more trade between the USA and the rest of the world.

Just the country itself. It means the rest of us have a choice or cheaply badly manufactured goods or we can use China, that’s why China are streets ahead of the US.