I have imported transactions from my bank and I can see that there are linked transactions which I assume is because I also have scheduled transactions. How do I find the transaction that matches the one I'm looking at so I can decide which one to keep?
A transaction with the link icon is one which was matched to an existing transaction. The data in that transaction will be the data you entered, whenever you entered the data. So the payee, the amount, and the memo are the things you wrote, not the things YNAB imported. And it won't link unless the amount matches the amount that cleared at the bank. So the transaction you see is the one you want to see--the one you entered.
The only reason to unlink it to see the imported transaction would be if you have reason to believe that the transaction is linked incorrectly, for instance, if you spent exactly the same amount at two different places within a short period of time. You can click "unmatch" to do this, but the odds are slim you need to. I've only had the situation I described above once or twice in 2.5 years of using the software. I would not recommend unlinking and re-linking all your transactions; it's a waste of your time.