Unanswered First layer prints with gaps

That is usually one of a few things. Start with under extrusion as the suspect.
Make sure you are extruding the correct amount of filament.

 

After you follow @mark tomlinson's advice to calibrate your extrusion then look at your slicer settings, most have a way to change the setting for only layer number 1. They do this so you can get better bed adhesion. Depending on your control program it could be in any number of places. You will need to look for it.

 

Still looks like this:

https://www.simplify3d.com/support/print-quality-troubleshooting/#not-extruding-enough-plastic

but perhaps this:

http://support.3dverkstan.se/article/23-a-visual-ultimaker-troubleshooting-guide#bottomlayer

(tweak the Z offset down for that one)

Also Check the extrusion width is not set to a silly value.

 

https://www.simplify3d.com/support/print-quality-troubleshooting/#gaps-in-thin-walls

and

http://support.3dverkstan.se/article/23-a-visual-ultimaker-troubleshooting-guide#wallspace