Hide "Follow [USERNAME]" and Followers on Widget?

You can’t hide the word follow. You can hide the count and the username if you want. Here’s info about what parameters the follow link can use: https://dev.twitter.com/docs/follow-button

You can add some of those parameters by adding code like this to another plugin or to your theme’s functions.php file:

function range_hide_follower_count( $attributes ) {
	if ( ! empty( $attributes['class'] ) && 'twitter-follow-button' == $attributes['class'] )
		$attributes['data-show-count'] = 'false';

	return $attributes;
}
add_filter( 'widget_twitter_link_attributes', 'range_hide_follower_count' );

You can add any of the attributes you find in that link