"What would I need to get..."

A Plumber.

You should use soapy water to locate any leaks. Check every fitting all the way to the stove. Also spray the tubing. If the leak is at a fitting use two wrenches to tighten that connection. Lowes and HD have pipe and fittings rated for propane. https://www.lowes.com/pd/PRO-FLEX-Pro-Poly-by-Pro-Flex-3-4-in-IPS-SDR11-x-100-ft-Direct-Burial-Underground-Gas-PIPE/5001521287

I'm surprised the OP's propane supplier hasn't flooded him over the years with blurbs urging calling them upon detecting any odor emanating from the propane system.

Also, besides hooking up to a corroded line, there is the potential risk (the photo needs to be more distant) of someone stepping on or tripping over the connection to the house. Such exposed connections should be black iron pipe, I have been led to believe.

The pipe is against the house and there is a cover that goes over it so you can’t step on it. And it don’t have a supplier it’s a small tank that I bring to get filled. I will use the soapy water and see if I can find anything g

Check the tank valve also. Since you refill. Look closely at the threads in the hookup for any dirt.