This year, in 2017, asteroid 4, Vesta will be the first major asteroid that will pass us in opposition. It will be the brightest and can be seen with the naked eye.
According to EarthSky.org, Vesta should be seen 90 minutes after sunset, low in the eastern portion of the sky. Check for the times in your area.
Check out EarthSky.org http://earthsky.org/astronomy-essentials/vesta-brightest-asteroid-brightest-for-2017