Well, if you're keen and your son is keen then there will no stopping you!
Many people recommend that a child have some time off after coming out of school before doing anything academic. Home education is quite different to school and it's good to have a break to adjust to the freedom of it. This is called "deschooling" and may be more important in the case of a child who has had a traumatic time at school.
If you aren't comfortable with that, another simple start is project work. You could let your son choose a few topics which really interest him - Warhammer, say, or cricket - and learn all about those topics. You'll find he ends up covering a great many subjects that way. For example, he'd be doing maths in using the right scale to build Warhammer sets the right size, or in working out his favourite cricket team's statistics.
Some families continue like that indefinitely. Even if you want to move on to more formal planned learning, then starting informally can give you time to have a good look round, maybe borrow some different resources to try them out and figure out which approach and which materials would suit your son best. People rarely have it all perfectly planned out before they start - or if they do, their plans may soon change as they discover what works and what doesn't!
Luckily you have plenty of time to find the right way forward and experiment with different ways of learning. Unlike a teacher, you have nobody looking over your shoulder wanting to assess everything you are doing at frequent intervals. You can take a relaxed long-term view. Lesson plans are optional!