Bikeracer2020
Super Moderator

It often seems to happen mainly in one area, search Youtube for under extrusion videos.

The holes look like under extrusion. There is a flow rate calulator in the calibration menu in Orca slice

There is a ready made adjustable temperature tower in the calibration menu in Orcaslicer

Try making the vertical height of your print a multiple of the layer height.

Just the free version with a limit of ten saved projects, a few features are disabled but it's adequate for my limited ability.

I don't know Tinkercad, but in Fusion 360 the spline tool puts nodes on.

You can scale the size up or down in the slicer before you print it. Max size will depend on printer build volume.

You need to download whatever slicer you want to use onto your PC. Import any files you want to print into the slicer which will convert them into...