Z-Scores & Standard Deviations confuse me, can you help with these topics?

Z-Scores & Standard Deviations confuse me, can you help with these topics?

ANSWER: These topics are so important that I made a three-part little video series. Hope these are useful! Please watch in order because I refer to the previous one(s).

Been having embed code issues so here are the links:

Part 1 : More on Z-Scores

Part 2: More on Standard Deviation

Part 3: Finding the Actual Z-Scores