Have a couple of games on the practice table, get used to the angles and attain your own speed and personal style; if you miss a pot and think, 'I should have potted that' then click 'undo shot' facility and have another go or two until your happy with that outcome.
Also, play 'Guests' from time to time, look upon them as sparring partners.
Above all else, forget about the points and play for the sheer enjoyment of playing; if you start getting obsessed with gaining points etc. you'll get angry and frustrated if things don't go your way and your not climbing the ladder as fast as you want to do..
take a step back and ask yourself, 'am I enjoying this ?'