If the token pair you want to provide Liquidity with does not have a pair yet, you can create it! Provide both tokens in an equal amount, and there you go. Since you are the first liquidity provider, you can set the initial exchange ratio/price of the tokens (if, again, the pair does not exist yet on PartySwap). Anyways, this will quickly correct itself through organic arbitrage and by more liquidity providers that jump into it.