Hello
There are several things to consider when choosing a transistor.
The current that the transistor must pass.
The voltage at which the transistor must operate.
Transistor operating power.
Transistor type, appearance and dimensions.
Transistor inventory in your market.
You see, transistor BJT is cheaper than FET, but it has more power losses. FET transistor is more sensitive to noise! And there is a possibility of more burns.
Regarding the type of N or P: The type of N is more varied due to its easier construction and higher quality, and also due to its function, more circuits can be set up with it.
It is better to decide first whether you want N or P. Then consider some of the transistors available, and choose the best one.
Specify your data by writing down the requirements of your circuit, such as voltage / current / power / resistance, and the shape of the transistor, then select the best transistors by studying the datasheet. You can also see the characteristics of transistors in the comparison section of some store sites.