What is the best tips to use while soldering?
There is no reason to get a silver tip.

Get yourself a good standard tip that has been primed with the proper coating, such as tips from the major brands (that usually only fit the major brands of soldering gear well, tbh). My Weller tips last me years, especially if you have a small € 5,- can of activator to re-activate the tip once in a while when it doesn't have the solder stick well enough any more.

Fun fact for all you tip-material-geeks: Some very cheap cast iron tips or similar can actually be activated to work for a couple weeks with Cooper Tools / Weller tip activator. Tried it for a friend once, who had a €7,- plug in iron that had no wetting action. Because the tip was garbage. After activator it worked for a couple of weeks. I do not doubt other brands will work too, but I got stuck to this brand in the 90's :-)

The causation for silver tips is/was maybe a bit of lore around the whopping 2% higher thermal conductivity, but probably the higher inertness of silver compared to copper, but first of all: Most major brands don't use pure copper any more and second of all they are coated to protect. So as long as you don't bend or actively scratch cheaper tips you will probably not notice the difference. And if you do, in 6 to 12 months it will corrode away and you spend €4 on a new tip, rather than having a €50 tip for the 3 to 5 years you'll be happy with this model of soldering iron.