Most home educators I know had kids originally in nursery or school and brought them out. My oldest was in a play group that firmed up my decision to do so but school is pretty different to nursery so I wouldn't liking or not liking one as the main criteria for picking home education. Almost all of the home educators I know are on low income, there are tons of cheap and free resources out there and what I spend is similar to what I'd spend on uniform and supplies and other stuff for them to be in school. It can be expensive but there are certainly ways to do it on a budget.
There are tons of programmes that can help you teach subjects. I was dreadful at maths at school and all my kids over 7 can mentally add and subtract faster than me. It has gotten more challenging as they've gotten older - my eldest is 12/year 7 and we've had a few times this last year where we've had to slowly work things out together (thankfully his maths programme is mainly online and checks it all for him, really reduces arguments). I can give recommendations on what worked here or you can check how home educating forums like well trained mind (US based but great for discussing issues and finding resources). Honestly, I find subjects I was good at at school (English and Humanities) harder to do because I knew I would have trouble with maths so sought out resources for that early while stuff I thought I had in hand I've ended up looking for help later for my kids that learn differently than I do.
There is no set curriculum - home educators don't have to follow the National Curriculum or anything else; however, if you plan to have them enter school at a certain point (Year 9-10 is common for GCSEs as it's getting harder to do them privately - we have a UTC locally that at least my older two are planning to go to for Year 10), you'll likely want to keep an eye on it when they get close to it.
The social aspect does take a lot more effort when home educating - I don't find it secluding and my kids and I have far more time to do what we enjoy and make our own friends, but effort does need to be made to find and continue relationships that isn't there in schools where you see people every day - it's different, with its own pros and cons.
Honestly, the main concern I see in your post is that your partner wants this and that's falling to you. Home educating has it's pros and cons, but if the person doing most of the effort isn't into it I would think the cons would feel a like bigger.