Selvage stitches are just an edging so it looks neater. I'd slip the first one and knit the last one. Blocking is washing the piece and then laying it out to dry in the shape you want. In the pattern you're looking at blocking would 'open up' the fans. It's not absolutely necessary but it will probably make the design stand out more.
What yarn fiber are you using? If acrylic...or acrylic blend...blocking may be somewhat pointless. But with natural fibers it can make a diff.
Eccie is correct on sel sts. But you can sometimes change them to something you prefer. Practice on swatches. A sel st used on garment pieces that'll be seamed is diff than those that'll be exposed, such as on a scarf or afghan.