All right, so I am in a similar boat except that we are married and have kids. The kids are twins who will be 1 in April and one baby on the way who should arrive in July. We've got some time to plan this out. My husband is open to the idea of homeschooling but, similarly to your gentleman, would like some assurances on certain areas. The main ones for my husband are socialization and the actual mechanics of making this work day-to-day. He has some concerns about academics, but more that I don't have experience with how young children learn or how to teach to that over actual content. Here is my current plan:
Day-to-Day Schedule - I'm researching all the different styles of homeschooling and figuring out what sounds best to me and what I would feel comfortable using as a starting point. Different styles end up with somewhat different looking schedules. Right now I'm looking at a mix of traditional and Charlotte Mason because, while I love most things Charlotte Mason, I really want more structured science and language arts too and I'm not sold on the timeline of language arts subjects in CM. I'm also researching how people structure their days/weeks/years and figuring out a loose idea of what sounds reasonable to me. I'm collecting free printable schedules too. Once I have this more organized, I am going to present it as a plan to my husband.
Academics - I really love curricula. It is just so cool to look through all these programs and see the different methods and ideas behind educational instruction. I'm browsing through different ones and making a shortlist of the programs I am most interested in. These would be my starting points as they may or may not work for the kids once they get into them, but they are ones that I consider appropriately rigorous and that I am comfortable teaching. My biggest concern is a full elementary language arts program. I know how to do the literature aspects, but the actual teaching how to read I'm not familiar with. However, there are a lot of resources out there for every subject and it's a matter of finding what works for you. Once I have a shortlist and it is time to plan, I'm going to go through them all thoroughly with my husband.
Socialization - My kids are 10 months old and not yet born, so it's something to ease into right now. But! I have gone through and found the numerous secular homeschool groups in our area and saved their contact information for when we get there. To help assuage my husband's concerns, I'm slowly getting the twins into play groups and will continue to do that as they get older too. The goal is to show that I have a working social network for the kids. Neither of us think that spending all day, every day with peers is only way to socialize, but we do want them to be comfortable with peers and have friendships. As far as dealing with adversity, I think that in any group situation, there are going to kids that bully somewhat, are adversarial somewhat, or generally do not get along well with your kid. They will learn to handle it and you can offer guidance more readily.
Character - This is something my husband has not mentioned but I have my own concerns about it! If I am going to be the person our kids learn from and emulate beyond the level of Mom (which is super important anyway), but Mom and Teacher, then I should be the person I would want them to learn from. I'm currently working on my "bad habits" and training myself first. Hopefully by the time they are old enough to start emulating more thoroughly, I have already developed better habits.
Commitment - Again, not something my husband is concerned about yet, but I am because it's me doing it! I'm working on gradually scheduling our days more and having a more solid rhythm to the home. I feel like this will naturally morph into an acceptable homeschooling schedule and lifestyle. With toddlers, there is only so much structure, but it's more that I am keeping things regulated throughout the day/week and that this habit becomes ingrained.
My basic advice would be to recognize your shortcomings and put a plan together to rectify them sufficiently. This should help prove your commitment and ability to your boyfriend. He should also go over things with you as you develop some plans, like the scheduling, curricula, and goals. And remember, these plans are all a starting point and can surely change as you have kids and learn how they learn best!
And for one last thing, make sure to see what is required by your state and have a plan to address that all as well. We are in Michigan where anything goes and we don't have to report anything, but many states require some level of documentation.