>>7002819You don't need to necessarily putty or paint. Just glue the pieces together, lightly sand the seam to try to get it as smooth as possible, then hit it with a nice matte topcoat (this will both make your kit look way nicer, and help hide the marks from the sandpaper). I recommend Tamiya TS-80, it's the flattest matte I've found and gives the plastic an almost velvety-smooth look. It's not that much work to be honest, and it should probably be your next step up after learning to panel line.
Pic related, bare plastic vs. matte topcoat.
