First off, welcome ! Secondly, this looks like an all extract kit, meaning that the fermentable sugars and OG (original gravity) are basically a done deal per given volume of the recipe. If your volume came in under the target amount, you could've just topped off with water to hit your target. Do you have a hydrometer ? I hope so. You need to check gravity - once a day over three successive days - until you have reached a steady reading. This will mean fermentation is over and it's safe to bottle the beer without having bottle bombs.