Hi,
From your description it seems as though the digitizer (touchscreen) is cracked and is no longer working.
Is the display still showing a good picture or is it cracked as well?
If it is only the touchscreen then this can be replaced.
Unfortunately I cannot find a guide or a video online that shows how to replace the digitizer, you may have better luck in finding one
Here’s a link to the ifixit [guide|41135] guide, which will at least help you to gain access to the display and digitzer.
Here’s a link to just one [https://www.actablet.com/replacement-touch-screen-for-skytex-skypad-10s-sp1020-dualcore-101-inch-tablet-pc_p11367.html|supplier] of the replacement part. It is only shown to give you an idea of the cost of the part. There are other suppliers online that may suit you better. Just search for ''Skytex SP1020 digitizer part'' to get results.
If this seems all too daunting, contact a reputable, professional electronics or mobile phone repair service and ask for a quote to repair the tablet.