salaam u alaikum
look, it is known the the consumtion of alcohol is HARAAM-forbidden, no matter what, so if the person knows this, then they are to abstain from it completely. i'm not going to provide all the evidence (hadeeth and quranic verses), as it will take long, but i will just get to the point. regarding prayer, the person shouldnt wait for friday prayer to ask for forgivness, start asking from now!!! the Five daily prayers are to be established as soon as you hit the age of seven, but if someone hasnt been praying then they should start as soon as possible, and yes, i have heard that any duah which is made between the adhaan and iqama is accepted, and Allah knows best. you shouldnt worry about dying intoxicated, because if you are reading this and sober right now, then just dont ever drink again, and make the intention in your heart to stop for the sake of Allah SWT. Start praying from now, and asking Allah for forgiveness. noone can say Allah wont forgive you, and noone can say He will, that is completely known by Him the All mighty and All merciful. Just have hope in your heart that Allah will forgive you, and have fear that He wont, and remember, we are all judged according to our intentions. :) if you like, my email is [email protected], so if you have issues or anything, or need help with anything, i can help, In Sha llah
May Allah SWT have mercy on us all and save us all from the torment of the grave and in the hereafter, Amen