Seems like the clutch is out of adjustment
If I am not mistaken your bike has a clutch cable and does not have a hydraulic self adjusting clutch mechanism. I've included some clutch maintenance tasks for you regarding adjustment and lubrication.
When your clutch is out of adjustment you get the symptoms you describe. Also, you may want to check your idle and make sure it's set at the proper RPM. When your idle is high AND your clutch is dragging a bit you can loud 'CLANK' when you push it into gear with your foot lever.
Your pressure plate where the throw out bearing washer goes, is made of aluminum. If you don't have the washer and the throw out bearing operates against that aluminum it will eat into the pressure plate quickly and ruin it. If that has happened, get a new one. It's done. If it hasn't happened, make sure you assemble in the right order and have that nice steel washer against it to protect it. This has been the source of a grinding sound when I have seen a failed throw out bearing on this model. Of course, I can't be sure if that's the case with you.
First, the handle for the clutch on the handlebar always squeaks. He bought two
lever landings before he finally took my advice and used a graphite dry lubricant on it. It comes in a spray can and has a liquid carrier that evaporates rather quickly leaving behind the graphite. Any excess can wiped off afterward. Apply liberally.
2nd, use the graphite to lubricate the cable inside the housing. It's super messy if you do it wrong. It's super messy if you do it right. Take the cable off the lever before doing this so you can get the lubricant inside of the cable housing. DO NOT ever use an oil based product to lubricate your cables. It will get stiff over time, especially in cold weather as the hydrocarbons evaporate slowly from the oil. It will get gummier and stiffer until it's unbearable.
On the handlebar
Adjusting a clutch cable on a motorcycle is an art form. You need to take your time and move the handlebars to the far right and left stops and check your adjustment each time. You want to have a little play in the lever. When you turn your handlebars far right on that model it WILL take up some of the play. You will need to adjust accordingly. When the handlebars are pointed straight there should be play in the clutch lever. It might seem a bit wonky but it's correct. Of course, you will want to keep the play to a minimum. Hence the art form. Find balance.
At the clutch cover
Perhaps I should have put this above but what are doing is adjusting the clutch at the point where it joins your clutch cover with the adjustment and locking bolt. Be sure you have the second bolt to lock down the primary in order to keep your adjustment from changing. You will want to adjust here and at the handlebar. You want the clutch adjustment screw at the handlebar to be about halfway in the landing, you find the point by adjusting at the clutch cover, then you fine tune the adjustment up top.
You should have a big mess of graphite down here because you did such a great job of getting the liquid graphite into the cable. If you don't have a big mess, you did it wrong. Wash, rinse, repeat. You cannot have enough dry graphite in the cable housing.
If you lubricate properly and then take your time adjusting the clutch with a warm motor, I believe your drag issue will go away. It's painful and manual but it's a beautiful analogue motorcycle that requires you to love on it. It's analogue and cool. Good luck.