When I print anything, the lines in the bottom and top layers don’t fully connect. I have attached a picture below for reference. Could anyone explain why this is? Is this normal?

Assuming that your nozzle temperature is correct for the type of filament you’re using, I think it’s under extrusion, try to increase your extrusion multiplier a bit.

If it happens only at the bottom maybe you’re too much close to the bed for the first layer.

It seems like your Z-Axis is not extruding enough filament between layers. Sometimes I get this when I print at .3mm (300 micron) layer height and the gap between layers is too big for the extruder to fill. You can solve this by decreasing the layer height to .2 or .1 mm. Hope this helps!