Regular school goers please helpb

I from a dummy school and have maths boards in 2 days ....My maths regarding jee is okayish , like 50 in mocks and got the same in first session too , have solved the adv pyqs of all chps ....for boards I have just seen the formats of answering and haven't practiced anything specifically ...Tomorrow I have thought of attempting any 2024 paper as mock....Please give any useful tips for writing the solutions as it has been 2 years since I gave any written maths exam ....and if u are any regular guy who has given exams in school , do u find the time sufficient to complete the paper easily in 3 hours ? Like in physics I had completed the paper when just 2 minutes were remaining....