well, you ASKED for accessories..& got a lot of opinions on what you should get, or spend your $$$ on.
My choice for accessories would be 1st.. a quality drop in trigger, or a trigger job by a skilled gunsmith.
You could waste an Lot of ammo, shooting & training, and a lot of money spent on other accessories ( I don't consider ammo an accessory)
on other suggestions, but a decent drop in trigger will be what improves the accuracy of your shooting, more than anything else.
If you read much, you'll find what I wrote is true.. I didn't come up with this, but my experience provides supporting evidence .
I target shoot, so must haves are a scope & mount,(for aged eyes) bipod, ( for old man shakes) and because I reload..a brass catcher is really nice.
What was said that is true, what you use your rifle for , should / will determine the accessories you need.