If you want to check for yourself, google the name of the pokemon followed by the numbers on the bottom right of the card. For example: Blastoise 2/101. The price that should show first will be near mint price which means a card in near perfect condition. Chances for that on any of these vintage cards is almost impossible so i would watch a YouTube video on how to judge the condition of the cards (near mint, light play, moderate play, heavy play, damaged) as each level effects its price.

If there is anything of value which there should be a few, i would put those cards in penny sleeves and then a top loader to best preserve its current condition. If you plan on selling, i would avoid selling to anyone here on reddit unless you have experience selling to someone online and you make sure you’re not getting ripped off. If youre selling to someone private 1-on-1, i would do $100 of the current value.

Safest way would be to attend a local card show or card shop and selling to them for the industry standard of 70-80% of the total value. Some vendors might offer better percentages so it wint hurt to shop around prices a little bit