Within Fibonacci Numbers
Jelly, 10 bytes
0ÆḞ©w¥1#;®
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How it works
0ÆḞ©w¥1#;® Main link. Argument: n
0 Set the return value to 0.
# Call the second link to the left with arguments k = 0, 1, 2, ... until
1 one match has been found.
¥ Combine the two links to the left into a dyadich chain.
ÆḞ Compute the k-th Fibonacci number...
© and copy it to the register.
w Yield 1 if n occurs inside the Fibonacci number, 0 otherwise.
® Yield the value stored in the register.
; Concatenate the index and the Fibonacci number.
Python 2, 56 bytes
f=lambda n,i=0,a=0,b=1:`n`in`a`and(i,a)or f(n,i+1,b,a+b)
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Perl 6, 30 bytes
{first :kv,/$_/,(0,1,*+*...*)}
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first
is a function that returns the first element of a sequence that passes a test, and it conveniently takes a :kv
adverb that tells it to return both the key (index) and the matching value.