mixing 2 mono to 1 stereo

Hi !
My sound card has 2 inputs and gives a stereo signal when recording, left side for the first input. right side for the second input.
I wanr to record 2 guitars playing the same riff, one on the left side, the other on the right side.
When i have recorded my 2 guitars, i’ve got 2 stereo tracks with for each : guitar on the left and nothing on the right. OK ?

I’m alone to play the 2 guitars, there is not 2 guitar players, ok ?

How can i do to have only one stereo track with each side playing a guitar? Is it clear ? Thanks

So when playing the clip, one could hear one or the other guitar moving the balance control…

With each of the stereo tracks, split to mono, then delete the silent tracks …

The make the two remaining guitar tracks into a stereo pair …

Great! Thanks!