I'm glad to hear you bf is giving sobriety a try, great news.
As for what to expect, everyone is unique so each recovery will be a little different too.
My RAH has been sober for almost 6 months. He did have a slip about 3 weeks ago, but it was a few drinks and he got back on track the next day.
The first 2 months were a bit trying as had boundless energy and just could NOT stop talking. (drove me up a wall!) He seems to have leveled out more now.
Mine also refuses AA, but seems to get as lot from reading Rational Recovery books. He talks about going to therapy, but hasn't yet.
I find Alanon very helpful and SR has saved my sanity. I don't know where I'd be without all the kind people here!
What you do for yourself will have the greatest impact on how you weather this. Take good care of yourself physically and emotionally. Read as much as you can about this disease and make sure you have some emotional support. Stay positive and hopeful, but always be prepared for a possible relapse.
Many do recover and become better people!
Wishing you both all the best!