If you want faster, cheaper results go with Europe, specifically non English speaking or Tier 2 countries.
Running Google Ads for SMM panels is already a massive headache because Google frequently flags them for fake engagement or circumventing systems. If you target the USA you're walking right into insane CPCs, cutthroat competition, and super strict moderation. Your account will likely get suspended before you even see a decent return.
By targeting Europe and localizing your ad copy into languages like German, Spanish, or even Eastern European languages, the clicks end up a lot cheaper. Competition is lower and the manual review process tends to be a bit more forgiving outside the primary English markets. You'll stretch your budget way further and your ads have a better shot at actually staying alive.