I like a handful of your nature photos. Most of them have decent composition. If you’re serious about doing photography, yes, invest in a DSLR if you are able to. But you need to take classes or at the very least do lots of self-study about the technical side of photography. Your portraits are not really portraits at this point, more like snapshots. A lot goes into making a portrait. Usually more than nature or landscape shots. You are quite limited with the point-and-shoot. You have potential as long as you are willing to put forth the effort!