In order to get married, do we HAVE to get a marriage license? Or can we have the whole ceremony without the legal stuff involved?

So me and my fiancée been together for 5 years and have 2 beautiful children together. We want to get married so bad but we have been holding off due to the marriage license.

Reason being, I will lose mine and my childrens health insurance, and I can’t have that happen.. so we’re thinking of still having the wedding just without signing papers. Is that possible?

Another question, I know after you get married the income becomes 50/50. So how does that work if we’re not legally on paper married? I think ahead, and I hope nothing ever bad happens to him but people at times pass away from things they can’t control at work or even car accidents.. if that does happen to him how will my children be covered and everything be passed down to them? Due to the horrible things going on with the sex trafficking and disgusting people, I will not work, and won’t have a stranger watch my kids, so cause of that reason I’m a stay at home mom & he brings in the income. I just want to make sure that my kids are set and even make sure that I will be ok, but it worries me and my fiancée because we don’t know if it’s possible for anything to be passed on to us, money wise if something was to ever happen to him.

I don’t know if this makes sense. Hopefully someone can help me.