Welcome.
You are correct to try modifying the temperature, the fan, and the printing surface; you've obviously been doing some research. These are all good things to try. Since you have a Plus, I assume you can also heat your print bed. Depending on the material you are printing, this can be a real help. It's
possible to print PLA without a heated bed, but heat will make it easier. I think I've seen references to people using around 70C for the bed. If you're printing with ABS, then heat is an absolute necessity - about 110C (don't touch it when hot!). Nylon and T-Glase do nicely at 70C.
Cleanliness of the bed is important: blue tape is no good if you have fingerprints all over it. Clean it with rubbing alcohol. And I think the general consensus nowadays for a convenient "adhesive surface" for printing is to use glue stick (the kind kids use in school).
However, the best-prepared bed in the world, at the exact best temperature still won't totally solve problems of adhesion. You need to have the clearance between the nozzle and the bed adjusted very precisely. A change of 0.1mm can make the difference between great adhesion and poor adhesion. I think that's what you need to work on first.
There's a "survey" of posts about getting good adhesion using different printing surfaces here:
viewtopic.php?f=16&t=7033Good luck!