Need advice for strategy

Hi, I need advices on game tactics. Recently I played games with other players and I believe to be equally matched with them. I am aware that I have no solid game and strategies to rely on Usually I hit the ball back to the opponent's side and trying to go side by side.

Here are my problems that I realised from the previous matches I played:

- On my service game, with the help of a good serve and the ball lands short and slow, 80% of the time I can to put the ball away; but sometimes my opponent guesses right where I hit. In this scenario, should I look at the opponent's position quickly, then get to the position to hit the ball? What is the method to send to the right spot?

- While playing a point, I got control of the ball and seemed to dictate but the opponent defended so well that he put all the balls in the court with lobs and slices. I continued to attack side by side, then lost through netting or hitting out. Should I stop the offense and put the ball in like he did?

I am aware that placing the ball is the priority and power is an enhancement to winning points, but I seem to lose track everytime I am being outplayed. Therefore, I am asking for advices on tactics in singles.

For sure, I need to train my shots. I am still not very comfortable with volleys and drop shots; backhand is sometimes off.

I would appreciate videos and articles on those techniques.

Thank you.