Welcome!
firstly you'll need to figure out what size bonsai you like, and work towards that. Now if you like small bonsai (mame under 10 cm, shohin under 20cm, gifu under 30 cm) then you could nearly start the development stage of this tree. If you are after something bigger you'll need to feed and do structural work. since its autumn and assuming you want to develop a small bonsai, you can start with a needle pluck, and since the tree hasn't been worked, the needles are long, so you can cut them down to about half. you can start feeding the tree with a mild to medium strength nitrogen fertiliser, preferably organic. this is a summary of my guide the JBP outlined here:
https://hakujuenbonsai.com/blogs/blog/t ... f54f&_ss=r
feel free to get in touch if you want further help.