Issues on my first 3DBenchy boat - PETG - Ender 3

[vitalbir 0]

I bought an ender 3 Pro to learn to print and be able to help make face shields for my country. I've always worked with CNC Milling, so I have some notions about printing, but a lot is new to me.
After two days of doing many tests, attempts and reading a lot on the internet, I got a satisfactory result from the boat.

 

 

 

the text below was not very good, it seems that the adhesion of the first layer was weak

 

 

But I wanted to understand what are the errors in it and how it could improve, I have no ideas to try (increase temperature, decrease fan speed, etc ...).

Printer: Ender 3 Pro

Filament: PETG

Bed: creality tempered glass (using the hairspray)

Nozzle: 0.4 (the standard that comes with ender 3)

Slicer: Ultimaker Cura 4.5

Settings:

• Layer Height: 0.2mm
• First Layer Height: 0.3mm
• Line Width: 0.4mm
• Wall Thickness: 1mm
• Wall Line Count: 3
• Z Seam Alignment: Random
• Printing Temperature: 240 ºC
• Printing Temperature Initial Layer: 235 ºC
• Build Plate Temperature: 75 ºC (but after about 30 minutes of printing, I saw that the boat was detaching from the table, so I increased the temperature to 82 ºC and it seems that it helped not to come off completely, I a previous attempt the boat has completely pulled off from the bed)
• Build Plate Temperature Initial Layer: 85 ºC
• Print Speed: 40 mm/s
• Infill Speed: 20 mm/s
• Wall Speed: 20 mm/s
• Travel Speed: 150 mm/s
• Initial Layer Speed: 17 mm/s
• Initial Layer Travel Speed: 200 mm/s
• Retraction Distance: 6mm
• Retraction Speed: 40mm/s
• Fan Speed: 20%
• Initial Fan Speed: 0%
• Z offset: 0.05

 

I tried using Z Seam Alignment = Random, after I was using the default and got this result (which I didn't like):