I wish I had kept my cards. I had binders and lunch tins full of Pokemon cards when I was younger. A lot got sold at garage sales while I was growing up, but I may still have a few left somewhere.
If you ever do sell them, I’d recommend only selling to a shop as a last resort or if you need quick money. I usually start by trying to sell on Facebook Marketplace since you don’t have to pay fees or shipping and get the most profit. On the flip side, you usually need to wait longer due to the smaller number of local buyers, and you have to deal with annoyances like people haggling for obscenely low prices, asking you to drive far to meet them, or just not showing up to buy the item. After a while, I usually list the item on eBay which means less profit due to fees and shipping, but usually more buyers and a smoother experience.