Wear new bifocals full-time to make yourself get used to new pair. Retrain yourself how to hold your head for close-up viewing. Change the head angle when eading books. Don't view things far away out of the bottom portion of the bifocals.
From the beginning you'd better not wear them for a long time, just for a short time.With the time go on, you can increase the time for an hour each day so that your eyes have time to get used to bifocal glasses gradually.Remember that the bottom part of the bifocals is used to magnify things so it looks closer to you than it is.You must be careful when you go up and down stairs during the adjustment period.
It takes time to get used to bifocal glasses.So you can get used to them gradually.At first you don't have to wear them for a long time, you can increase the time for wearing bifocals day by day. I believe you can get used to them soon.