Need advice pls

Hey guys! There’s three of us going to a festival this summer. We each have a 4g bar of mushroom chocolate. Me personally have only done a small amount of mushrooms in the past but am very experienced and comfortable with acid ( sadly couldn’t get a hold of any) so we are opting for the shrooms instead. Looking for advice more than anything on how much to take, can I continue to take more during the day, and best way to store it until the festival and to the festival as not to loose any potency. I’m sorry for the beginner questions I just can’t find many straight answers online.

Little more context, we are in the uk and we have been to this festival many times so am comfortable with the set up and where everything is. We are going to do it on the Thursday as not to be too overwhelmed. And we will be smoking a fair bit of weed on it also. Just need guidance on best way to go about taking it. Thank you all. I appreciate it!