"overloaded" means there are many different versions of the print() function. There's one that prints single characters, there's one that prints strings, there's one that prints String objects.
"ambiguous" means it found two different versions that might do what you want but it's not able to tell exactly which one. The compiler can't guess which one you wanted. It has to stop and ask you to be unambiguous.
Printing an array of floats is probably not what you wanted. If you have 1.23 and 4.56 in an array, do you want it to print "1.234.56"? You should probably print only one of the values in the array at a time. Then print a comma or space between each one. Use a for() loop.