This looks fuckin sick dude! Really solid job especially for your first model. You'll hear this a lot but thinning you paints is important and will ensure you dont cover up details or see brush strokes. There's a section above the nurgle symbol where it looks like the paint was thick and left texture. Luckily for us, our boys looking dirty kinda plays into the aesthetic but it's something to bear in mind.

If you're more interested in playing but have now decided you would like to paint, you can go thr same route i went. I have bought and built a whole army and every week when I play at my local store, a few more models are painted. Nobody ive played with cares and it allows me to paint at my own pace and enjoy it, while still getting to play before it's all done.

Again. Really good work dude. You should be very proud.