Rather than just take a box of coins to a Coin Dealer to get an appraisal, it is best to try and organize your coins by Country, or if they look they are all US coins, organize them by denomination and by year. You could then take them to a local coin dealer in individual boxes. (And by the way we do not buy or sell the coins themselves)
BUT if you really want to get the most value out of the coins, we suggest putting them into 2x2 Coin Holders. These come in various sizes to fit the coins you need and you are able to put notes on the cardboard portion to further understand and document what you have. Once you’ve done that, then you would be more prepared to contact a coin dealer and let them know what and how many coins you have.