If you're trading it in at a dealership, probably have nothing to worry about. However, you're probably not getting the best deal. The tractor supply is coming back, but people are still looking for good quality, affordable, tractors that they don't want to wait for: sell it privately.
When I buy or sell something with a value over a few thousand, I know it's easy to get scammed. You're doing the correct thing by asking for advise. But too much advise can be overwhelming and confusing. So here is mine to add to the pile!
If you are accepting cash, get one of these
pens that I'm sure you have seen used in stores. Check the bills. It's not fool proof, but I highly doubt your potentially crooked buyer (who is buying a tractor) is sophisticated enough to bypass this test.
You can accept a personal check, but I'd defiantly hold on to the tractor until the funds have cleared. This is not ideal, and most people understand when you tell them "no personal checks accepted."
Consider a direct wire transfer from the buyers account to yours. Just be careful about giving out things like your account number, routing number, etc. Contact your bank or credit union for help. Be aware that many people do not know this is an option and/or know how to go about doing this.
Use a service like PayPal or Cash App. There are limits though, and protections typically go to the buyer. This is not ideal as there are steep fees associated with using these services. PayPal has a limit of $60k per transaction.
You can do a cashiers check, which is common and mostly secure. Just know that when the guy shows up to see the tractor, he might already have an envelope full of cash. Going back to the bank on a weekend or taking time off work, etc, might be too painful for the buyer, who already has the money in hand. Might screw up the deal.
Not a popular option, but I like to use it, is bitcoin. Have the buyer buy the amount of the agreed upon price in BTC and transfer it to you. This is probably the safest and most secure method. You could then simply sell the BTC (potentially at a gain) for USD directly into your account. Some cons with this one is limits. Currently, Coinbase has a buying/selling limit: $10K per transaction. Might take a few transactions to get the payment through. But if your willing, and the buyer was sitting on a pile of BTC, might be the best bet.
You can accept any form of payment, for any goods or services, so long as you both agree upon it before doing business. You need to protect yourself no matter what the payment method in the form of a Bill of Sale that should include the make, model, SN (of the tractor and loader if equipped), date, agreed upon price, and both parties signatures. Make two copies, one for each party. It wouldn't hurt to snap a photo of his ID and offer yours in return. Trust is gained on both sides when people exchange trustworthy information.
I'm sure your transaction will go smoothly and securely. Have some faith in people, but always remember: "Trust. But Verify."
