Hello! I have a few questions related to NMR that I would love clarification on, thank you so much!

 triplet

The arrow points to a CH₂ carbon (two hydrogens on that carbon).

Its adjacent carbons are:

one CH on the left → 1 neighboring H

one CH on the right → 1 neighboring H

So total neighboring hydrogens = 2

Using the n + 1 rule: 𝑛+1=2+1=3

So the signal is a triplet.
Splitting is done by the magentic field of neighbouring(adjacent) carbons hydrogens.