I wouldn't recommend sewing a jacket for a first time costume sew.... What I would do is buy a jacket an then modify it w sewing for the chain and such. As far as the skirt, there are some great simple skirt patterns at Joann's, just look for sewing level 1, maybe 2. As far as material, it depends on budget....
Adelheid (KHR!)- 85% done
Fem!Austrian War Succesion France (Hetalia/Nyotalia)- 10% done
Fem!Izaya (Drrr!)- 90% done
Magent!Teto (Vocaloid)- 95% done