<p>Anet A8 with Cura. First time use. The extrusion temperature is set at 190 °C for PLA but the temperature never quite gets that hot, e.g. 189.2 °C. So the printer never prints.</p>
<p>The bed temperature is fine.</p>
<p>Any suggestions on how to fix?</p>

Two common problems to look out for in this situation:
Make sure that your
part fan
(the fan that is supposed to cool the filament you just extruded, and that does not start spinning until the print starts) do
not
blow air on the hot end of your extruder.
Make sure that your
hot end is well insulated
.  If available for your printer, silicone sleeves are the best:
otherwise the most common, universal and low-cost solution are cotton pads: