Stick a thermometer in the vent. Should be around 50-60°F coming out. You’re potentially low on refrigerant. Any frost on the coil box (usually above the furnace)?
Unfortunately this is 100% not user fixable. Typically requires specialized tools to diagnose and then fix. You also can’t buy refrigerant without a license.
Not legal and definitely not easy to get local without a license. There’s always someone will to sell on the black market. Also, shit is dangerous if you don’t know what you’re doing. I was trying to give the OP sound advice, you know, what they’re asking for.