Beginner at guitar, and your playing sounds even worse than you think it should? Try tuning your guitar – it might make you suck less!
This string goes back to previous methods. You know the drill by now: next tone, move five semitones to the right or play the fifth fret of the B string. This thinnest string will be tuned to an E. It will be precisely two octaves higher than the thickest string, and using this is a good diagnostic test if you tuned the guitar to itself. If the thickest and thinnest strings match, you should be all set. If your guitar has 24 frets (most don't) then the 24th fret of the low E, and an open high E should sound the same.
This string will be tuned to A. Again, if you're using a tone generator, simply switch to the next highest note and get cracking. If you're using a keyboard, move right from the E you just used until you encounter the first A. This will be five semitones higher than the E. Follow the same process as before for this string. If there's no other instruments/options about, you can tune a guitar to itself. It is less accurate as the intonation could be slightly off, but it's usually more than close enough. Play an A (fifth fret) on the E string you just tuned, and tune the second string to that pitch. Then move on to the next string.
The high E is usually written in lower case to avoid confusion with the low E, which is why you'll often see the tuning system you just conformed to described as "EADGBe". This is by no means the only method of tuning a guitar, but it is the most universally recognized. If you're interested in "drop D" tuning, you simply need to lower the low E string two semitones. You can do this by playing a B on the low E string, and an open A string, and then adjusting THE E STRING down until it matches the A string. This tuning is largely used in rock/metal as it makes power-chords easier.