There are plenty of different types of displays out there,even within the major categories"
LCD ,Plasma,or even good old Cathode Ray tube (CRT)!
What kind of TV,old,new, brandname,model number,year of manufacture?
If it is an analog CRT TV,I'd say."Don't bother",as the chance of finding a replacement tube is small,& for a noob,fitting & setting a new tube up is a nightmare.
The news isn't a lot better for LCD or Plasma,unfortunately,as again,fitting & setting them up,is very messy.