Need help deciding on good insurance plan

I am a single, self-employed 32 year old woman with no dependents. I am looking for a health insurance plan that will cover annual doctor visits, well women and labwork. Also, mental health and dental/vision. Whenever I go for checkups, I just like to get a full panel bloodwork and STD test to make sure I am healthy. I am hoping for a plan that covers labwork like this. I am doing some shopping online and it’s all a foreign language and I have no idea where to start.

I also want a good plan that will help a lot in case I am diagnosed with something very serious. The reason I am shopping now is because I found an odd lump in my breast. I am trying not to freak out. On that note, if say I enroll in a plan next week before I am diagnosed (if worst case scenario it came to that) how does that work in terms of treatment coverage? Would they pay for treatment if I just recently enrolled in their coverage? Should I even wait for any kind of diagnosis until getting enrolled in a plan?

Thank you for your help.

About me:

Single

32

No serious health concerns

Don’t drink or smoke

Currently only need 1 SSRI RX a year for depression/anxiety

Like to visit doctor, dentist and eye doc once a year