Pick your poison. 9/11 conspiracies, ancient aliens, Russian espionage, flat earth, spirit science, masons, the Illuminati, whatever. On the internet, you can find someone willing to tell you anything, and weave a tapestry of words and images to support it. If you don't take the time to seriously examine both the evidence presented and the reasoning applied to that evidence, especially if it is an advanced subject, it is easy to be duped.
Don't fall for confirmation bias. Just because something aligns with your preconceptions, that doesn't make it true. Test with the intent to discredit. Seriously consider alternate arguments for cause and effect. Remember that post hoc and cum hoc arguments are fallacious for a reason. Partisan or national allegiance also blinds us to reality as we toe the party line instead of considering the matter at hand dispassionately and rationally.
Conspiracy theories are fun, but the burden of proof falls on the one making the extraordinary claim, and extraordinary evidence is necessary to support such claims. Further, regardless of the validity of such claims, consider the ramifications. Is it something within your sphere of control? If not, knowledge is not worthless, but obsession can be unhealthy, and time used in pursuit of falsehoods or groundless speculation cannot be recovered.
Credulity is "readiness or willingness to believe especially on slight or uncertain evidence." Incredulity is the inverse, a trait of skepticism and disbelief. If your first instinct is to doubt, you are far better served when new ideas are presented. I do not mean to suggest a sort of belligerent refusal to accept truth, but that truth must be proven.