Mike
Cogs are on the rear wheel chain rings are on the front. As far as cadence is concerned, higher is better, especially when climbing. Way easier on the joints. As far as style of climbing is concerned you have a choice of two, sitting or standing, or combinations. Each uses slightly different muscle groups. Seated you spin your way up .Standing is slightly lower cadence than sitting but usually in a higher gear than sitting. The one advantage of standing is you can use your weight to generate power, the draw back is that you have to use energy to support yourself, which tires you out faster.
So, go find a nice long hill, and climb it. then turn around and climb it again. Do it seated then do it standing keep your cadence high. Style, fitness. and the rest will work itself out.