FF7 is quite an easy game... if you've had it 12 years, then you never picked it up and played it until now lol. Just the fact that you don't know what materia is, is evidence of that.
The game isn't really that hard, it's more like it's not simple. Once you get the hang of all the subtle ways you can tactically make your characters more efficient, the more the game becomes exponentially easier.
You said you had trouble beating the Scorpion? You probably attacked while it's tail was up. You see, the scorpion does not attack at all while it's tail is up unless you attack too. So that means that as long as it's tail is up, you've got an opportunity to use potions, keep your guard up, and maybe change your characters positions [Front/Back rowing] without the worry of being attacked. Then when it's tail is back down, you resume shoving your foot up it's @$$.
You said you had trouble beating the timer? Now this one baffles me... as I've beat that timer in under 3 minutes several times. When I'm feeling lazy and barely try, I still beat the timer in under 6 minutes.
Are you getting lost in the reactor or what?
Maybe you aren't running from battles? If that's the case, just hold in R1 + R2 on your controller when you encounter a battle until your characters run away. This should buy you lots of time to get out. I'm guessing that this is your problem. Also do not forget to help Jessie get his foot unstuck, going back for him is a massive loss of time too.
It's simple things like this that you need to know in order to play FF7 without frustration.
One huge tip I have for beginning is always to learn to utilize the Front/Back Row feature. When you're in your party Menu [Opened with Triangle], select Order. The White hand should appear above a character [Usually Cloud]. While it's on Cloud, hit your OK button [This is by default O, but... Did you also know you could customize your button config? I always swap X with O, because it seemed backwards to me.] again and it should start flashing. Hit it one more time while it's flashing and Clouds pic will shift to a different position.
What did you just do, you ask? Well, it mostly depends on what side you're attacked on, but most enemies attack on the left... so it's best to keep your healing/ranged characters to the right [This means they're in the "Back Row"] and your heavy hitters to the left [This is Front Rowed]. Anyways, I digress, I'll explain what this means.
Front Row: Characters in the Front Row do more damage, but also receive more damage.
Back Row: Characters in the Back Row do less damage, but also take less damage. However, Ranged weapons/characters do not receive any back row damage penalties. So always keep Barret Back rowed while he's using a Gun [Some of his weapons like Cannonball aren't ranged though].
That's why. You wouldn't believe how significant it really is to winning battles easier.
Do keep in mind that some enemies will attack from the right... when this happens, your parties positions will be reversed. If this happens in a boss battle [The one that comes to my mind is the Tank boss after you escape from Shinra HQ], either start over so you can reverse their positions or you can do the following in battle.
When it's your characters turn, you can do 1 of two things instead of Item/Magic/Summon/Attack. You can actually either "defend" or "change". Defend means your character loses their turn, but takes less damage while defending until next turn. Change simply changes your character from front to back row and vice versa. You can defend by hitting the right arrow button while on a characters action menu [In a battle ofc] and another little window pops up saying [Defend]. Select that. Change is the same exact thing, but is the left arrow button instead.
So when you face bosses who show up on the right, you can quickly change your characters positions to better suit that enemies position.
I realize this thread is dead, but maybe this info will help someone out down the road.