I have visited Mysore city in summer 2018. Problem is the most cleanest city in India. To go to Mysore you can board a bus or train. There are lots of busses and trains available in Banglore city.
Its just a two hour travel from banglore. After getting down in mysore you can either board a bus or you can book a package which are cheaply available in the city.
The most important places are mysore palace and brindhavan gardens.
Don't forget to wait till 6 o clock as you can see the mysore palace full of lights and thats the best moment we can get in the mysore.
If you visit banglore then dont forget to go to mysore.