If you have zero experience fixing old tube electronics, consider getting a cheap (say, $5) old tube radio at a thrift store or garage sale and practicing on that. Replacing capacitors is not rocket science, but not everyone enjoys that kind of thing.
We all made beginner's mistakes once upon a time; better for you to make yours on a throwaway item. This also avoids the risk of frying some unobtanium part in your television.
If you succeed in that little project, you'll have more confidence working around the TV, with its higher voltages and greater complexity.
Just a thought . . .
Phil Nelson
http://antiqueradio.org/index.html