First of all, make sure the lenses have the correct prescription and can fit you well. In fact, it does take some time to get used to monovision contacts, maybe several weeks. Some people may need at least a couple of months to get used to them.
Yes. It is a little difficult to get used to monovision contacts. In most cases, people will spend eight weeks on getting used to them. Some people can get used to them in a week. So that is determined by your own condition. However, if you stick with it, you will get used to them very soon.
When I wear monovision contacts for the first time, I always get blurry vision when reading. And I keep on wearing them for a week. Later I can wear them with no problem. I believe you can get used to them very quickly if you insist on wearing them.
Yes, it need some time to get used to them as one lens is for close and the other is for distance and your brain can't coordinate very well between them. Once getting used to monovision contact lenses, the two eyes will coordinate to see close-up and distant objects as well as bifocal contact lenses.