Tennis' basic rules are as follows:
If you don't like the scoring rules (15, 30, 40, game, set, etc.) or are pressed for time on court, you can still play tennis with your own different scoring rules. Playing shorter sets (i.e. four games per set), tiebreakers, or with volleyball/badminton scoring rules will help you save time and prepare for real tennis matches too. Try to focus more on the quality of your strokes and less on the scoring rules. Then, in time, the official scoring rules will be an easy and comfortable switch. (Do try to play with one-bounce, court boundaries, serve and other rules to the best of your ability).
As a side note, watching tennis on television, reading books on tennis or playing tennis video games can also help you to learn tennis rules and strategies. As my website demonstrates, learning does not always have to happen on court! 😎🎾
Below is a preview of the tennis basics and rules webpage from Tennis Canada that was recommended above. Scroll inside the embedded window to see the full page, or click the redirected link at the top of this page to view it in a separate tab.