Upcoming Presidential Candidates

I am almost sorry for asking, but this year has brought me about 60-70 hours of work a week it seems, so I am unaware of much that is going on in the world. I know an important election is coming soon for president, and I am prepared to cast my vote as I did last time. I have heard of many names that are running as Democrats, but I have yet to hear of anyone running as a Republican. Does anyone know who is running as a Republican, and what are your thoughts on those who are running? I want to make sure that I make the right choice for president, as we all know this coming election will be very important in determining the future of our country, especially for us gun owners. Any help is appreciated.