Hi. Welcome to the Ranch!
As long as you're declaring the loop counter in the loop expression (that's what the
for(int i = 0;... bit does) then the scope of that variable is limited to the loop. So if loops don't overlap then you can use the same name. And if they are in different methods there's definitely no problem - variables declared within a method can't interfere with variables in other methods.
But when you've got nested loops you need different names. On your line 10
you should be able to refer to both counters, so you need to be able to tell them apart.
While you're at it - using
i for a simple loop counter is usually fine. It's pretty standard usage. But once you start nesting loops it's easy to get the indexes mixed up, so I'd usually suggest trying to give them more meaningful names.