It varies hugely, depending on the child's interests, needs and aspirations.
E.g. some people i know of that age are mostly using an online school to get them ready for a pile of GCSEs, and that probably takes 2-3 hours per day. Some have tutors in for an hour or two once or twice a week. Some are following a curriculum at home with parents, maybe just for maths and English and something else that is their special interest.
Some aren't ready for getting ready for GCSEs. They might be doing some formal education, but at a less advanced level. They might also be doing quite a bit of life skills or vocational activity and volunteering alongside a parent (e.g. at a city farm, at an old folks home, in a toddler group or home ed group aimed at little children, or learning how to look after themselves at home - cooking, cleaning, laundry, budgeting, meal planning, gardening etc).
Quite often there are bits of activity in the local home ed community they can join in with, for sports, gaming, board games, art, drama, music etc etc (depends on the skills and interests of those in your local area). It can take a bit of time and digging to hook in with those sorts of activities, partly because some teens are off organising their own activities, and partly because such groups tend to go a bit under the radar to prevent invasion by enthusiastic newbies with tiny children...
Some people get a season ticket (e.g. national trust) and just squeeze every drop out of trips out, being relaxed and chatting about the experience as it happens. That can be exactly what a new home educated teen needs to relax and get their mojo back and start being curious again.
NB really important to give your child time and space to recover from whatever made you pull them out of school.
Does this help? Take your time to work out what will work for your child, and give them as much time and attention as you can.