In that case I would strongly suggest you upgrade to 7.3.7P3 as there are a lot of bugs that have been fixed since 7.3.5*, especially with regard to SMB2 support
You should ask your partner/reseller if you need help with upgrading, even though it's rather easy (download new software, install on filer, do takeover/giveback 2 times) there might be dependencies on other software (SnapManager or other 3rd party tools) that you might need to check, and your partner should be able to help you assess these issues.
You can check if smb2 is enabled by entering
NetApp> options cifs.smb2.enable
cifs.smb2.enable on
If it's on, you can disable it with
NetApp> options cifs.smb2.enable off
and re-enable it with
NetApp> options cifs.smb2.enable on
The settings take effect immediately, and if you have Windows clients that were accessing the filer through SMB2 when you disabled it, these clients might need a reconnect with SMB1, which will happen only after some time (depending on the Windows version and settings it can be up to 15 minutes) or a client reboot (usually faster than just waiting). It should not affect existing sessions but since windows continuously tries to disconnect and reconnect, you should be prepared to expect these long timeouts.
Auditing is a bit more involved, you should probably skim over the relevant documentation (File Protocols Access Guide) and over the basic Windows concepts before trying to implement it (misconfiguration can under some circumstances kill your performance or fill up your root volume with tons of logs)