Connecting takes about ten seconds. It lends this integration your account's daily LinkedIn API allowance — nothing more — and there is nothing to set up afterwards.
The permission you grant is scoped to LinkedIn Ads data only. It gives no access to anything private on your account — and that is a limit LinkedIn enforces on the connection itself, not just a promise about how it is used. It cannot read your messages or connections, see anything personal on your profile, or take any action as you. The connection simply does not have that reach.
Your name and email, once, when you connect — only so it is clear whose connection this is and who to contact if it ever stops working. You will not be emailed otherwise.
Connect LinkedInYou can disconnect at any time from LinkedIn › Settings › Data privacy › Permitted services, and the allowance simply stops being used.