Does anyone really understand.......

the voting system in the U.S.? Okay, the reason I ask is this. I have only voted in one Presidential election. Don't insert gasp here, I only became a U.S. citizen just in time to vote in that election. I have tried to figure out the entire voting process, including the electoral college. I read everything I could on that particular subject & all I came up with was a massive headache, eyestrain & the urge to crack open & imbibe the entire contents of a bottle of Pinot Noir. Though this result does not fully explain the process, it does explain some of the laws & government at least in this state. No sober person could have come up with some of this stuff.
With the upcoming primary election looming for I believe 22 of the states in early February, I chose to vote early. Now, with candidates dropping out (or were they pushed, maybe the electoral college knows) here & there along the campaign trail what happens to the votes people have cast early that are for a candidate no longer running? Are they simply discarded? Those voters should get a second chance. Wait no, I'd like to change my vote. Like electives in school ; I'll have the Libertarian for my 1st choice, but if that's not available I'll go for the Republican. Is that your final answer? May I poll the electoral college?
By the way, where exactly is this college? Is it near WhatzamattaU ? Is it on top of Mt. Crumpet? Some elusive island off the coast of Bora Bora perhaps. I'd like to go there. The college & Bora Bora really. With a bottle of Pinot Noir.