When you shop for a guitar you want to first consider the genre and functionality of what you will be playing. Are you mainly a lead player? Or, are you playing rhythm only?
If you are in a Folk band or doing a solo gig, a Yamaha Acoustic would be nice. Now do you want a plug-in or use a microphone. Many acoustics are what they call electric-acoustic meaning the body is essentially acoustic but you plug it in like an electric. There are steel or nylon string versions in the electro-acoustics category.
If you play classical a Takamine or Cordoba are great sounding and fairly affordable. Dauphin is a Spanish brand that plays extremely nice.
The Fender models including the Mustang, Stratocaster and Telecaster have most chime-like and unique character of all electrics. These have typically the smooth alder body and lightning-fast maple neck. These axes are the premier and authentic sound for country-rock being played by everyone from Eric Clapton to Yngwie Malmsteen.
The warmest sounding of the Electrics are definately the Gibson models. You can't beat the solidness and craftmanship in the Les Paul. Talk about big bold sound, everyone should own at least one of these beauties!
I would have to say though that the Kramer Striker, if you can get a used one, is the most expressive instrument ever! It has great speed and agility combined with an extremely responsive Floyd-Rose Tremolo system. For a lead guitar rocker, I consider this one a must have!
When you go to the music store you want to take your time. Go when you have a free day and you can focus on the task. Of course you have little choice these days but to go to the "Center" but at least there are tons of instruments there for the pickin'.
First get a strap and get the jam-stick reasonably in tune. Try playing in different positions up and down the neck. Make sure you are comfortable playing lead and rhythm (chords) on the instrument.