Gold coins are a way to store value in a small, easily portable form factor but precisely because of the high value it might be difficult to use them in time of need. How to buy supplies if the grocer can't make change for a Maple Leaf, for instance?
If you buy gold coins you're making a bet that the world will remain normal enough that you could get fair value if you wanted to cash them in.
Silver coins would be more practical for actual spending, assuming you were dealing with someone who understood their value. The downside of silver coins is that for the same value, they'd be much, much heavier than gold.
IMHO the first precious metals to invest in are good tools. Quality tools, for a variety of needs ... and skills to go with them.
For the same price I could buy a few silver coins, a pretty sterling teaspoon, a good Swiss army knife or a cast-iron pot good for cooking things over a campfire. Each would be useful in its own way and I want some of each!