Easy tool for designing card template?

I need to print about 300 cards for my prototype and each one just needs to have basic text on it (no longer than about a sentence per card). Ideally a template that lets me print 9 cards per page and easily edited. This seems like it should be very simple, but I feel like I can’t find the right tool!

If someone could point me in the right direction that would be great I’m pretty clueless here