You're just a crazy person for not holding any Bitcoin or Ether, and yes it's called Ether and not Ethereum if you're talking about the currency. There is a substantial lack of knowledge that most people have in this space and by all means I am not particularly knowledgeable. I'm quite the novice to be honest, but I make it a point to learn and understand these technologies.
First, people don't understand and don't appreciate the fact that all crypto currencies are not the same. It's not that "crypto" is just a cool or cute way of saying internet money. It means cryptography, which is a method of protecting information and communications through the use of code.
Each coin is really quite different. Ether, for example is the currency for Ethereum. Ethereum is a DIY platform for DAPPS - decentralized programs that no one controls. Think peer to peer file sharing is an easy to understand example.
Ethereum is a platform not a currency.
It's a bunch of computers working together to form a super computer to power DAPPS. Ether exists to help pay for the maintenance of all this. It incentivises people to run the Ethereum protocol on their computer.
This is not the same as Bitcoin, or Bitcoin Cash or Light coin or USDC. Before you put any money into anything really learn what the technology is behind the coin and if it's something you believe in or not.
I personally think Bitcoin will be digital gold and it's something you won't sell but can leverage against. Ethereum has the potential to become a global super computer. How valuable would that be?
What to do for total beginners
Alright, so if you have not idea what to do I suggest opening an account with a brokerage: Coinbase, Kraken or Gemini. Buy Bitcoin and Ethereum. Move it to your own wallet and hold.
Once you get a bit more comfortable, you'll want to use a brokerage account like Coinbase and a platform like Voyager and Blockfi. At Coinbase, convert your cash to USDC. Then move that USDC (which is a coin pegged to the dollar) to Voyager where you can easily buy and sell without paying crazy fees.
You can also use Blockfi to hold your assets where they earn compounding interest, even USDC. Just know that Blockfi is not FDIC insured so there is risk involved.
Now, you're setup to to buy and sell fast and you should be making compounding interest.