Could just be a normal muscle strain / some minor soft tissue damage. It's early days with regards to injury so my advice would be to rest it for the next 1-2 weeks and pop some heat on if sore (heat pack or hot shower/bath). Some gentle calf stretching may help but if bending your toes is painful at the moment, I'd ease off on this for at least the next few days. Any muscle / soft tissue injury generally heals up fully within 3 weeks, so give it some time.