~snip
I just tried to practice through etherscan and it seemed like it was very easy. I use someone ethereum address that I chose randomly, because so far my ethereum address has no assets.
Here are the 3 steps:
1. Copy and paste the ethereum address where you want to know the balance in the search box.
2. After you find the ethereum address and click on it, the next step is to click on the display column of view exspanded ERC-20 token holding.
3. The final step is that you only need to look at how much the available balance is at the address, whether some ERC-20 is worth or not.
Source image:
https://etherscan.io/#Please try and have a nice day.