Luck just refers to whether you’ve found more or less blocks than expected.
If your power/difficulty equation suggest that you should find one solo block every 100 days, but you find one in 50 days, you have been lucky… but if you mined 200 days before finding one, then your luck was low. If it took you 100 days, then you were neither lucky nor unlucky - you had 100% of the expected “luck.”
Luck is a measure of what happened (in the past). So as soon as you find a bock, the luck calculation will shoot up.
If you’re mining a coin where you expect one block every 100 days, it takes a long time to build an average. If you’re mining a coin where you expect one block every day, then you can may see you luck change every couple of days, or even a couple of times in one day.
This mostly needs to be done with your wallet software, which should tell you if a wallet address is invalid.
If a wallet has received funds before, you can check it on an explorer. If it’s a new address, you can send it a tiny, tiny amount = 0.0001 BTG - and then check the wallet on the blockchain to see if it went through. (And maybe also confirm with the recipient that it’s correct, if the other party is new to crypto, also.) Once your test payment goes through, you can feel more secure when making a larger payment.