TS4 is almost a pickup'n play game ; TE2011 is a simulation. The former is easier & faster to get in, the later requires more time to get good at. So it's normal you get a hard time when you play online if you didn't spend a few hours training against a CPU with a decent level (ie: you should beat the Junior-10 before to put a foot in an online match
About the matches against the CPU : start at a low level, take your time, there's no rush..!
Play a bit in warmup to get the hang on the controls, then do a few training club matches till you can beat the default CPU player a few times (its start level = Beginner-10). Be sure to use the Danger Zone & Aiming preview at 1st, but turn off the Aiming Preview when you start to get used to the timing needed to aim left/right from near the baseline, from far from the baseline, & from the net (they're all quite different).
Once you're very good at the game (or if you like high difficulty), you can turn off the Danger Zone preview ; it is recommended to keep the ball bounce preview though, as it can be hard to guess the ball trajectory on a monitor (ie: no stereoscopic vision like in real).
Then you'll be ready to read advices to avoid to be aced too much => topic8-6180.php
Against the CPU, just step a bit more back, that should be enough in lower difficulty levels.
And don't hesitate to read the doc, it contains a lot of useful information about how to play & what-not : http://www.managames.com/tennis/doc/Ten ... e.html#how
If you want to play right away in the World Tour, the default settings are too hard : before a match, lower your opponent level to Beginner-10 (instead of Club-10), that should greatly help you to get the hang on things (this + the helpers).