newbie: how to get larger keys on lockscreen keyboard? background: LG model=L34C (virtual keyboard), Android version=4.4, on which I am the opposite of "power user" :-(

Basically I'm fat-thumbed. I don't want theming or photographs or animations on my lockscreen, I just want to type my password with {more speed, fewer mistakes}. (And, no, I don't wanna switch to PIN or pattern or biometrics for my lockscreen--I do want decent security for this thing.)

My understanding (which could be very wrong) is that the lockscreen must display in portrait mode (i.e., long side vertical). Is that correct? If not, please lemme know: making the lockscreen display in landscape by default seems like the easiest way to get what I want.

Alternatively: must I install a lockscreen app? If so, please recommend one that Does What I Want: display time and date in as little space as is {feasible, readable} and devote the rest of the space to the keyboard (preferably in landscape, but I'll take what I can get).
Considering that you responded in the comments that landscape-only is alright, I'd suggest Ultimate Rotation Control. Use its "Forced Auto" mode to rotate any apps to any direction you want - that of course includes the lock screen. After proper settings, it could seamlessly integrate with the built-in rotation switch too (basically you could toggle the built-in switch and the lockscreen will now obey).

On my devices, when I have a password set and lock screen rotated to landscape, tapping on the password textbox will show a full-screen editing interface with landscape keyboard, which should be good enough for your fingers.