Two key techniques that take you from an absolute beginner to someone who sounds like they know what they are doing.
Fretting hand muting is an essential – simply because it stops your fingers hurting. If you don’t want a note to sound, just rest your fingers on top of the strings. The percussive *thwack* that you get from strumming sounds great, and gives you time to sort that chord change out.
Palm muting (which is done using the edge of your strumming hand, not your palm! silly guitarists…) is a means of controlling the ringing of open strings, and is often used in support of fretting hand muting for particular effects. A gentle palm muting makes your guitar sound more percussive, which can be useful for various styles, or to add dynamic contrast to a song accompaniment.
Further topics on request!