Of the naked-eye planets, fast-moving Mercury is always the most challenging to observe, because it's usually lost in the Sun's glow. Our best opportunities to catch it occur at eastern or western elongation, when its angular separation from the Sun is greatest and it's far enough away from the glare so it can be seen shortly before dawn or soon after sunset. As July opens, Mercury is about a week past greatest eastern elongation and is located in the evening sky, setting about an hour after the Sun, but the low angle of the ecliptic (the plane of the solar system) causes it to appear very close to the horizon, making it difficult to see in the glare, even near elongation. Eventually disappearing into the glow by mid-month, it reaches inferior conjunction on July 21, when it passes between Earth and the Sun. Emerging into the morning sky in early August, it reaches greatest western elongation on August 9 when it rises about an hour and a half before dawn. It's visible before sunrise until late August, when it retreats back into the Sun's glow and disappears behind our star, reaching superior conjunction on September 3.
The thin, waxing crescent Moon passes near Mercury on July 3 and ordinarily might help observers to find the elusive planet less than an hour after sunset, but both will be difficult to see in the twilight. The next encounter between the two on August 29 will be lost in the Sun's glare, and the following meeting isn't all that much easier to see just after sunset on September 29, when Mercury sets only 40 minutes after the Sun.