Fondasharing open prisons (Cat D) are not for minor offences, but for lowered risk prisoners, including successfully rehabilitated murderers coming to the end of their sentence, who can leave the prison to attend work nearby. Your friend won't find so much education and training facilities within such a prison as the idea is to plug into what is available beyond the prison. That includes taking home leave in hostels or with the family, where appropriate, in order to set up employment, education, training, voluntary work or to show a responsible lifestyle can be maintained on release. Many open/Cat D prisoners attend college or paid/unpaid work five days a week.
In local, training and high security prisons, there is a massive programme of training and education for prisoners, with in-house staff, contracted colleges and promotion of Open College and OU participation. Some prisoners can be trained as literacy and numeracy mentors, to support other prisoners on an individual basis. Of course, prisoners have to engage in offending behaviour and drug/alcohol treatment programmes, see doctors, solicitors, visitors, chaplains or whomever is relevant for them, so there's a lot that can be crammed into their days that can divert them from benefiting from education.
If your friend discusses his concerns with his personal officer, education staff or probation officer, perhaps they will help him find what he can do to participate or contribute.