Gadget

Thanks so much what could've happened if I connected them up together

So I decided that I was going to build my own PC, I'm new to this whole thing And was wondering if I had chosen the right parts. The photo below shows the parts I choose and I'm unsure mainly about the power supply (like how much Wattage I'd need) if someone was to be so kind and tell me If these parts would all go easily together that would be great. THANK YOU (I do realize the Mouse and keyboard and OS isn't here , I plan on buying them locally)