Although there are many people who would like to be a presidential candidate , there are many requirements. For one, you need to be a born citizen, then you need to be at least 35 years old, and lastly you need to be a US resident for at least 14 years.
The first step are the Primaries and Caucuses. Because there are many people who want to be President, people with the same beliefs are grouped together into the same political party. After campaigning, in a caucus, the members select best candidate through votes and discussion. In a primary, the members vote on the best candidate to represent them in the general election.
Each party then holds a national convention to elect their final candidate, and at the convention each candidate chooses a vice president candidate, after which, the candidates campaign throughout the country trying to get support from majority of the population.
Next comes the general election. People from every state in the country, go and vote for one president and one Vice President. As people are voting, what they are actually doing is voting for a group of people called Electors.
Each state gets a certain number of electors. Each elector then votes after the general election and the candidate who receives more than half, will win the election.
Lastly is the inauguration which is the ceremony when the newly elected president and Vice President are inaugurated and start serving their first term.