Well… first off, its not bad for straight out of the box. There looks to be some over-extrusion (bubbles on the surface). Try a flow rate of .97 - .95. The cause may be filament dependent… or variances in the filament diameter.
Try rotating the object 45 degrees and check if the lines in still appear.
I’d recommend a calibration cube for troubleshooting. They are typically 20x20x20mm cubes… I’ve attached a STL I use to check for dimensional accuracy the extrusoin tolerance. If you print a pair, they should fit together (.25mm difference between peg and hole) pretty tightly. If the peg doesn’t fit the hole, try adjusting flow rate to increase or decrease the tolerance.
Report back on the flow rate adjustment and rotating the object on the bed. Welcome to the FDM world!
-CalibCube v1.stl (86.4 KB)