Yep, you certainly can
Some lovely pics actually. One tip though - for landscapes switch to Aperture Priority mode, and try different apertures for each shot. The higher the f-number, the deeper the depth of field (ie more of the picture in sharp focus).
I took the liberty of cropping this one...
and changing the sky to something more sunrisey...
I boosted the colour, increased the contrast, changed the levels a bit, and sharpened it a smidge as well. So my other tip is to have fun with Photoshop