A few beginner tips:
1. Hitting the "ESC" key once clears the command line and hitting it a second time puts your cursor on the command line.
2. Right click in the command line and make sure "Command Line Morphology Help" is checked. This will provide the choices of characters you need for morphology searches.
3. Click on "Tools" right below the Command Line and look at "Command Line Examples" to show you how to do the particular search you are attempting.
Here is a BW seminar on video:
I haven't watched this particular one, but I watched another seminar on video when I started, and it gives you plenty to get you going.
Otherwise, just use it, experiment with it, try to figure things out from the help sections and videos provided with BW, and come here when you're stumped.
καὶ ὑπὲρ πάντων ἀπέθανεν ἵνα οἱ ζῶντες μηκέτι ἑαυτοῖς ζῶσιν, ἀλλὰ τῷ ὑπὲρ αὐτῶν ἀποθανόντι καὶ ἐγερθέντι.