I've been playing since I was 4, so can't really recall being a beginner, but I completely agree with the above. A couple of coaching sessions early doors will go a long way. I've recently gone to a few group coaching sessions despite having played for 30 years, and my backhand and serve have improved hugely as a result.
That said, a few straightforward tips for beginners:
- Either stand on or just behind the baseline, or at the net. Don't stand in half-court. If you do, you'll be trying to pick up a lot of balls bouncing at your feet, and it's much easier to run forwards from the baseline than to run backwards from the service line. Obviously it's not an absolute rule (eg if you're playing non-competitively against someone who's consistently dropping the ball short, move forward a bit), but in general it's one of the most important things to follow and something a lot of beginners get wrong
- When volleying, keep the head of the racket higher than the wrist. If you're volleying a low ball, bend your knees. As one of my old coaches put it, "move the machinery"
- Move your feet - get in a position where you're comfortable to swing through the ball. While lessons are a good idea, the swing in tennis is technically much easier than in a lot of sports. The hard bit is getting yourself in the right place
- Serving is probably the hardest aspect of the game for a beginner. Focus on your ball toss and where you strike the ball - try to throw the ball with a straight arm, as it will mean less moving parts and the ball going upwards more consistently. Throw the ball something like 1.5-2 times your height, and reach up for it. If you feel like you're hunching over when you serve you're hitting the ball when it's too low
In all seriousness, though, have a think about what you want to get out of it. If you just fancy booking a court with your wife and daughter don't worry too much about technique and just have fun - if you overthink it you'll get frustrated. But if you want to improve and learn the sport a bit, a couple of lessons early on is the best thing you can do.
@Spleen Sauce will know better than me, but presumably you can book some lessons for you, your wife and your daughter to do together which will save on money and mean you can keep enjoying it together.