Not a dumb question at all
Basically you do the right thing when choosing the weapon with the highest number.
You know what hitpoints are right? Well, if a sword does 1d10 damage, it means that you will do 1 to 10 hitpoints damage to your opponent, based on which number you "roll" (in real D&D, they actually roll a ten-sided die and the number you throw is the number of damage you do.) Now, 2d4 means, that you will roll two dice of four sides each. The number you throw is the number of hitpoints you drain from the opponent. In game terms, this means that when you are using a sword of 1d10 it is better than using a sword of 1d8.
Now, when a weapon is enchanted (for example a long sword +3) this means that you do 1d8 +3 damage. so your enemy loses 4(1+3) to 11 (8+3) hitpoints.
A critical hit means that you do double the maximum damage.
Hmmm I hope I haven't made any mistakes in this explanation, I'm no expert myself
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Melusine, High Queen of Fluffies, Archbabe of the Order of the Holy Flame and the Laughing Hyenas, &
Official Entertainer Elf of the BG2 Bar
Your voice is ambrosia