If you have the chance to go to a large guitar store, take a look at the Fender Strat, and the Gibson Les Paul. These two guitar models were basically the solid body models that started it all... (there were other guitars of course, but these two became almost the icons for rock 'n roll). While there have been many technical improvements and updates through the years, the Fender Strat and Gibson Les Paul are still very similar to what they were 50 years ago.

Try playing some "Squire" Strats, and Epiphone Les Pauls. These are their more affordable brands and versions of the higher priced Strat and Les Paul.

Most of the other solid body guitars out there leaning towards the style of the Strat or the Les Paul... so if you try both styles, and find you prefer one over the other, that will help you a bit.

In purely subjective (as in, it can be argued over easily) and laymans terms, my opinion is:

Strat: a bit harder to play, though reaching higher notes is easier due to the double cutaway. Bright... can be made to sound harsh but also easy to articulate each note.

Les Paul: a bit easier to play (the stretch for your fingers is not as much as the Strat). Versatile... can sound like a lot of guitars (just not a Strat, ha ha!). Can sound muddy, particularly on the "neck" pickup. Otherwise, rich, full tone.

Think about those things a bit when you try out a guitar... move the pickup selector around, and try the different sounds to get a feel for them.

For your amp... DO NOT buy a "nice, sweet sounding tube amp" as the sale guy puts it, for $1000 or more... instead, check out modeling amps like the Peavey Viper series. You can get a small practice amp super cheap. When you've cultivated your sound a bit more, then you can start looking at tube amps. For your church talent show gig, maybe look into renting or borrowing an amp for the evening... just make sure you understand how to use it and get the sound you want. You may also be able to patch your practice amp into the PA system, but again, a test and sound-check is essential.

For your practice amp, make sure it has this:

-a headphone input
-a "CD" or other audio input.

These two features will allow you to go online, download a bunch of jamtracks (there are tons of free ones out there) and then play them on your computer, with your computer plugged into your amp. You'll love it. It will feel like your guitar is right in the mix with the band, and is so much better than cranking it on a stereo then trying to jam along with an amp.