For us, as with so many things, it depends on the temperament of the parish. This is a tragedy. My parish - a very traditional and orthodox one - ordinarily requires a year of preparation for adult Confirmation. A priest teaches many of the classes, so we have plenty of time to ask questions and learn in greater depth. The children go through a couple years of preparation and catechesis before they are Confirmed. This is exactly as it should be. I’ve been pleased that my parish take Christian education seriously. Sadly, however, I’ve attended two parishes where religious education was basically laughed at as a thing of the past. As a result, the people of those churches are not growing as they should. Anglicans/Episcopalians are all over the map on this.
I think that it’s safe to say that the overwhelming majority of Christian bodies have failed miserably in this area. We all see it in our own circles. And it’s needed now as much as ever. Lord have mercy.
Yes, that has been my observation too.
Most Anglicans do have Sunday Schools, which use a variety of programs. Many are based on the lectionary readings. Some are better than others, to say the least.
Anyone who is going to be confirmed is supposed to learn the catchecism in the Book of Common Prayer, which covers all the basics. It is written in a question and answer format, and in the past some parishes just had the kids memorize the answers. Usually now, if they bother with it at all they do actually teach them what it means.
The priest is supposed to be responsible to ensure that the candidates are suitably instructed and must present them as such to the Bishop.
Adult instruction for converts is supposed to be based on the same criteria. Often there are not official programs for this. (This isn’t necessarily bad, it can work well for the priest to directly teach new converts, and in small places it often makes the most sense.)
There is a diocesan program here for couples being married but it isn’t absolutely required, and also a video for baptism which you are supposed to watch and discuss with the priest.
My parish actually developed it’s own Sunday school program for grades primary to six, and recently started a toddler’s church program. We also have a lot of adult study programs. So for Lent we had

raying the psalms with St Augustine", and we recently had a short class of a few weeks about the liturgy, one on the Anglican 39 Articles, one on Hooker (an Anglican theologian), and even one centered on movies about saints. Sometimes we have speakers - one I enjoyed was about the development of church architecture and sacred music and how they were related.