Did theymos remove support for Grin or was the link never added on the purchase copper membership page? According to his post, it's suppose to be there, but it isn't.

There is nothing wrong with your suggestion, but for someone brand-new to Bitcoin transactions, it might be easier to have a look at mempool.space at first. After that he can learn how to check the mempool manually. While I am writing this, we have only around 600 unconfirmed transactions in the mempool and a 1 sat/vByte is enough for a quick confirmation unless something changes dramatically.