Welcome indeed. Good to have a new user on board.
There are a lot of variables influencing render time, but I wouldn't start by changing variables like bucket size. Those are pretty much optimal at default. The filters make a harder or softer rendered image, so to say. If you use the search function and look for info on that subject, you'll find it. You can also test yourself in a crop render to see what the differences are. Very informative anyway to delve though older posts; there's a huge amount of experimentation and experience in those threads.
What Yossam says, the alpine shader is slower than others (due to internal computations), but things like transparent water (especially with a lot of displacement in waves), extreme displacements in land, easy clouds, compute terrains/normals after more than the usual number of nodes, and such, are also taking up quite some time.
My principle is to use as few as possible nodes and as few as compute terrains (in some circumstances a compute terrain is not needed at all, and that reduces rendertime). So build carefully and read and experiment a lot.
Btw. the max size on the forum is 6000px wide, so keep it below, and preferably in jpg.