You know that’s not how elections work, but if you’re genuinely interested here are some lists of third-party candidates in the US:
You can find comparable lists on the sites of many more non-frivolous political third parties in which you may be interested, which can probably be found from their Wikipedia entries.
This thread, specifically this comment, is telling you you should vote for alternative parties at state and local levels. The idea is to build up that third party’s actual presence in government from the ground up, which is a far superior strategy to splitting a critical presidential race and feeling like you’ve accomplished anything good.