You might have to go to a private rehab clinic to dry out. Some hospitals I think will take you in if withdrawing from alcohol will put you at risk of death. Otherwise, move to an area where you don't know anyone and can't access drugs. Kicking drugs might just be the first step. If you can quit drugs first, you'll be more powerful within yourself and maybe can use that to quit booze also.

Most likely though ultimately you'll need to deal with the reasons why you became dependent in the first place or over time you'll fall back into the habits. That means a good pscych.

All the best, you can do it, I told myself if millions of other people got clean, I can too. But it takes time and fall off the wagon every year or too still despite dealing with my root causes.