I recommend getting it professionally set up at a local suspension shop. Check local track groups to see which ones are good to go.
They will be able to give you a good baseline setup for your weight and make any spring/valving changes they deem necessary. Depending on how long it has been since the suspension was serviced (if ever), it might be a good idea to get that done too.
A lot of my local track events have a local shop there to do track-side setup/changes at a slight discount, and you can go back after a few sessions and talk to them and re-adjust as necessary. They know what they're doing and can really help find the root of any issues and explain the how/why of it all.
I'd wait to drop larger $$ on suspension upgrades until you confirm can't solve your problems on the current setup, especially since you're at a novice pace.