It's hard to give specific measurements for this recipe, because the quantity of sugar should vary depending on how much fruit you have and how sweet it is.
When I made peach jam I had 1kg of peaches, but they were so sweet, I only added 300gr worth of sugar.
For raspberries and blackberries I recommend adding half of the weight of the fruit in sugar, because they're usually not very sweet to begin with.
For the blackberry jam of the video I had
555gr of blackberries
the juice of one lemon
250gr of cane sugar
No need to add any extra pectin, berries have their own natural pectine.
If you follow all the steps of sterilization your jam will keep in the pantry until you open it, then store in the fridge.
Here's a video about just that! "How to Sterilize Jars - Real Italian Kitchen"