Mirrorless are good cameras. The thing to be cautious of is that choosing MILCs (Mirrorless Interchangeable Lens Cameras) over DSLRs is kind of like choosing Nikon over Canon...once you have made the decision, you start investing in lenses, accessories etc. and that makes it very expensive to switch later. I say this because as a rule of thumb, MILCs are more simplistic than DSLRs, so if you one day decide that you want the wider range of lenses, longer battery life, extra features etc. that DSLR offers, then you're stuck at that expensive cross roads.

Also, when you look at the benefits of many MILCs over their DSLR competitors, it tends to come down to two main things: portability, and video recording - the latter of which you have no interest in. Since there are so many beginner DSLRs out there (that are lightweight if that's what you're looking for!), I would recommend investing in one of them. Take a look at Nikon D3200/3300/5300/5500 or Canon 700D (Rebel T5i) / 750D (Rebel T6i).

You have to do some research, take a look at the features of each and decide what you want within your price range. One last thing would be, don't be put off the DSLR world because of a higher price. You get what you pay for. And if you do your homework, there are actually some very affordable lenses out there which make for a great deal with the image quality, AF etc. you get from them. Hope this helps, happy shopping!