Working on a Wooden Seating area

I posted about a month ago and thank all who responded.

I have now sanded down the sitting and back rest areas with 80 grit with an orbital sander. It has taken quite a while, followed the grain. Now I’m treating it with the Roxil wood protection for the winter coming in.

My question is to get some of the colour back like the areas that aren’t really affected by the rain will a straight coat of varnish help or do I need a wood cleaner first?

Much like my first post I am a first time garden owner coming from a small south London flat. So apologies for the absolute cluelessness.