I broke my left foot twice (the first involved several bones and was many years ago),...but the last time (in March) was my 5th metarsal. Depending on the severity of the break and any additional damage, you need to get some information from your doctor regarding how much weight bearing you can do.
Swimming isn't weight bearing but when you kick, you may find the plantarflexion of your foot causes spasms due to the atrophy of the muscles on the bottom of your foot. You'll also get a lot of fatigue, and working on simple balance exercises, like squats on a BOSU ball which you can buy in most fitness stores may help you strengthen the muscles in your feet and ankles and start strengthening your leg without any impact activities. Bicycling is another good cardio.
Doing
wall sits, squats, isometrics, physioballs,....again, all this because you mention not working out at a gym and seeking home alternatives.
Your
upper body will need balancing after being on crutches and after wearing a boot, so that needs to be addressed too.