There are 278 babies born every minute. 2-14 of them are trans, depending on various estimates. Every day, it is likely that someone is born who will one day grow up to have a gender unlike that of any living person, even if they are never exposed to the right culture and information to find this gender within themself.
There are not an infinite number of atoms in the universe.
Being that there will never be infinite number of anything let alone people, no there are not an infinite number of genders.
There are infinite possible positions, infinite possible sizes, and infinite possible numbers of legs.
That’s not how infinity works.