sorry, I am so busy right now that I entirely missed your comment ... .
I am using the native wallet, but that is not very user friendly. I heard a lot about grinbox, which is supposed to be much easier, but I have not used it yet. Getting GRIN is still not nearly as streamlined as bitcoin.
For trading, there is no really good exchange. I would recommend trade-oger. They have low volumes, but are as far as I can tell they are honest.
Now Grin pumped a lot, so I would probably not buy ....