Too much water,, adjust the stop float

If the toilet is old replace it. We've repaired ours many times but the new parts do not fit the old toilet well. If its newer, try to repair it. Lots of videos online. Look at the reviews for the parts.

Do you mean it takes a long time to fill the tank? Just to be clear, once the tank is full, you can flush twice using what's already in the tank and then the tank takes a long time to fill all the way back up? If that's the case, then yes, I'd consider replacing the valve which shouldn't cost more than $10. I replaced my valve via YouTube last year and it's still holding strong. There are also some instructions on how to clear debris that might be blocking your valve. That didn't work so I replaced the valve with a $7 part I bought from Walmart and 30 minutes later the valve was working great.

How long is a long time?

And I won't ask why you need a triple flush. . .

My toilet can flush twice but after that it takes a long time for the bowl to fill again. What could be wrong? I bought a new valve and will attempt replacing it via youtube. Do you think that could fix it?