Could I need head gaskets replaced?

Hi forum members, my name is Guy and I am new here so I am just learning how this forum works so if I do something wrong please tell me. I have a cub cadet zero turn with a Briggs 22hp Vtwin OHV engine. I just did the seasonal tune up on engine and when I checked the old oil I noticed it was just alittle low so I started looking at the engine really good. I pulled the spark plugs and they were black wetish/ oily on the left side head. Right side just alittle but both were black with oil on them so I put the new spark plugs in and When I started the engine it doesn't smoke hardly at all BUT I do have oil inside my muffler because I can see some smoke where it's burning off the inside of the muffler Once the engine was warm. I also noticed where the muffler tubes bolt to the heads has oil crud around the two bolts and while the engine is running I see little bubbles of oil. I had to look really close to see this happening as it wasn't really noticeable until I got looking at it closely. I cleaned the oil that was around the muffler tube where they bolt to the head as I thought it was from my valve covers were the oil. The motor starts and runs fine. The oil was a little low when I pulled the dipstick before I changed the oil and I made double sure not to put too much oil in the engine when I added the new oil. I have no oil inside my breather/ air filter area. I have read a lot recently since I noticed this issue and what I have read leads me to believe it's the head gaskets. I pulled the valve covers and I had oil In the push rod galley which I don't know if that's normal or not. So the engine starts up with no smoke issues and runs good but I am getting oil leaking out around the muffler tube bolts that hold the muffler to the head and I noticed on the left side head (facing the engine from the back of the lawn mower) on the left side bottom of the head as the engine was running on the fin that's closest to where the gasket is I can see oil running down the fin out

towards the wheel side of the head. This is very little oil I must add because I cleaned the fins which did have old oil build up on the bottom. Also when I checked my valves while I had the valve cover off the exhaust valve was tight and I needed adjustment . I am hoping I have caught this early and can save my engine. It doesn't knock at all. Just oil loss issue. If I wasn't so particular I probably could use it like it is but if there is oil coming out from these places I know something is wrong. Any advice would be greatly appreciated and I go

Hope i said too much and confused the issue. Thanks again for any advise.