I use them, pay them off monthly and have an excellent credit score.They are cash reward cards and while I’m told on here that isn’t wealth building and I agree, the amount that kicks over into my emergency fund is a happy thing for me. Coupon clipping isn’t wealth building either and buying something because you have a coupon unless you use it all the time or it is free isn’t smart but still fun to have the extra dollars if you would buy it anyway. All a matter of discipline and knowing yourself..
I’m retired, can live on my pension or even in a real pinch could exist on my social security, continue to invest as I did when I worked. Seems to me if credit cards are not a problem to you now and you both are on board with having one or two and paying off every month or only using every few months to keep them active and a good score would be okay. My opinion only. My homes are paid for, both residence and rental properties, am able to give. Your dream is a big one, wish you well however you make it happen. Just be sure to take into account that life has a way of dropping problems into your life along the way so you can’t count on everything always going smoothly.