How much energy takes C4 photosyntesis to make glucose?
Yes,C4 plants use 30 ATP molecules to make one molecule of Glucose.See since you have stated in your question that you know very less about biology and got some similar vibes from looking at your profile so I'll sum it up in a nutshell but hopefully this might help.In flowering plants,all of them follow a basic pathway know as the C3 cycle to make glucose from CO2.Now,in that process about 18  ATP is used.But apart from CO2, there's O2 also present in the atmosphere which interferes with the compounds taking part in C3 cycle and instead of CO2 participation O2 participates in the reaction and the consequence is that glucose is not produced and the plant wastes some energy in the form of ATP.

Now to prevent that from happening,some plants evolved themselves and made some chemicals which bind only with CO2.But the thing is that they also require energy to function and for each molecule of glucose produced they require 12 ATP this making net amount of ATP required to be 30 in a C4 plant.You can in a way visualise this C4 pathway that the plant placed some guards in the form of chemicals that combines with CO2 and makes sure it reaches its destination and to prevent traitor O2 molecules to disrupt plants from making glucose.But we all know that that guards would require some fee and so that fee is 12ATP.And visualise C3 pathway as some some sort of glucose making factory which makes glucose from CO2 and the production cost from raw materials is 18 ATP.