how to find specific component with ltspice?
For standard components like transistors, diodes, inductors and capacitors the selectable components are not inside the component placement tool, but in a separate dialog.

So you select your standard component (npn transistor in this case) and place it on your schematic.

After that "rightclick" it. A window opens with general information about the part. It also contains a button labelled "Pick new transistor". Click that button and you end up with this:



You can sort by part number or other parameters.

One thing to note though:

The library of parts is only that large - it doesn't contain everything you need (because it would have to contain everything, as I need other stuff than you do). So one skill you'll eventually have to learn is how to include a not supplied model into LT-Spice.

For some basic elements you can also set the spice parameters yourself with a CTRL + rightclick on the component and filling out the "spice model" line.