If you want to get into gun smoothing, invest in a hard arkansas stone. If a stone looks like a sponge, it's too coarse. Use it with oil to knock off any burrs and to flatten out the high spots especially on the circled parts. The bolt slide is usually the worst. Then apply a good lube like Triflow or Breakfree.
Realize that what you are doing is applying years of wear in a few minutes. Moderation is called for. Just a few strokes to knock of the burrs is what you want. Resist the temptation to think that if three strokes is good, then ten is better and that 30 would be perfect. If you decide that 50 would be the "Ultimate" then you can turn new, unfired gun into a worn out, unfired gun in an hour.
Just a knock off the burrs and a few strokes on the shiny spots. That's all.