You can still used ranged-for loops and get an index, granted it requires an extra bit of code.
int32 Index = INDEX_NONE;
for (const FItem& Item : Items)
{
Index++;
//WhateverHere
}
or you can use traditional for loop
for (int32 I = 0; I < Items.Num(); ++i)
{
Items[i];
}
Loops are pretty simple.