Vote for what exactly?
OP could use some actual details. As a non-American I would like to know what this is about.
But whatever I guess
The US typically has ~2 days a year where polling is open for specific local races... Usually state, county, city, or town races. Typically earlier in the year, states will have a primary for contested elections, or polling days earlier in the year (typically in March) are for local seats on specific boards or to affirm administrative appointments. Beyond that, though, the first Tuesday of every November (as long as that Tuesday is not November 1) is the traditional election day in the US and there are elections held every year.
This year there aren't many major national stories, really just two governor's races in Virginia and New Jersey that have national interest. Governors are basically the "president" of each state, the 'executive' of that state who will sign laws that state legislatures pass, oversee interstate business, approve the budget, etc. In the New Jersey race it has some national implications because the incoming governor of New Jersey is likely to appoint a new Congressman shortly, as a sitting Democratic congressman from New Jersey is embroiled in a bribery scandal, is going to be (or was already?) indicted, and may have to resign. If a Republican is elected governor, it's likely that he'll appoint a Republican congressman to fill the seat until the next election can take place, if a Democratic is elected governor, it'll likely be a democrat. Further, this race has some interest because the sitting governor who is leaving office when his term is up is Chris Christie, who was a Republican presidential candidate in 2016, but who was one of the first mainstream Republicans to endorse Donald Trump. While Trump has been outright rude to Christie throughout the years, Christie has become Trump's bitch and it was thought that he would be appointed to some position in the Trump administration because of his loyalty, but he wasn't.
The Virginia governors race is also being seen as a rebuke or affirmation of Trump, as the Republican candidate has run a very nationalist, populist race, much like Trump did, and it could suggest what is to come in 2018 if he wins.
Both Democrats have led in the polls, though the Virginia race is tight, just 2-3 points in most polls, which is within the margin of error and polling similarly to the presidential election last year. In New Jersey, the Democrat leads comfortably by double-digits in polls and is expected to win comfortably.
Otherwise, most elections are state and local elections. For instance, my city is electing a new mayor who will serve for 2 years, a new city council, and new school committee, who will also serve for 2 years. This is unlikely to be national, or international, news. There are no broader state-wide elections in my state in 2017, though some other states may.
Importantly, though, groups will often petition for "non-binding resolutions" during off-cycle elections. These are resolutions that are posed to get a sense of the electorate and voting trends... But many of them end up becoming binding resolutions in future votes. For instance, back in 2011 or so, there was a non-binding resolution to legalize marijuana in my state, which got well below 50%, but the trends and demographics suggested it was an issue that could pass in a major election... Which it did in 2016 when it became a binding resolution, which legalized marijuana in my state.
