Material_Complaint_7's journey

I recently had a couple of interviews that went surprisingly well. After a previous post seeking advice, I interviewed with one company and they said they would get back to me next week. On the same day, I had another interview with a different company that I was initially reluctant to attend due to burnout from the job search. However, I went and met with three managers, including the one I would be working under. The interview went really well, and to my surprise, they offered me the job! I signed the offer letter and gave them permission to run a background check. HR informed me that my official start date for onboarding is July 6th, pending the background check results, which I’m confident will be clean. Now, I’m in a bit of a dilemma. I need to give my current job a two weeks’ notice, which I want to do to leave on good terms since I don’t have any issues with my manager or coworkers. However, I haven’t received a copy of the offer letter yet, and I’m worried about the possibility of having my offer rescinded. Should I wait until I have the offer letter in hand before I submit my notice? I’m anxious about this because I want to ensure everything is set in stone before I fully commit to my move.