Currently, MetaMask may not have prices/fiat values for all tokens. Please be sure to check Coingecko or Coinmarketcap to verify whether your token is currently being traded/if there is a fiat value for it.
Note: if you don't see the dollar amount next to your token, this does not impact your ability to send the token to any destination of your choosing, nor does it impact your ability to swap the token (assuming there are markets with liquidity for the pair you are trying to trade). Please check the "markets" tab for the token on Coingecko or Coinmarketcap if you are unsure about where the token is traded.
Regardless of the token's fiat pricing or lack thereof, you still own these tokens and they are yours to do with what you wish.