In general, yes.
I'm not familiar with your soundcard, but you may run a signal from a guitar pedal, directly into your soundcard, record with software, and mix & edit within the software environment, all within the computer.
You don't necessarily need an outboard mixer to do this, as described, but an outboard mixer might help if you've got more complex sound mixing needs. [You'll know when you reach this point].
In simple terms, yes, what you said is basically correct. Your guitar pedal signal may be fed into the soundcard, and do the rest with software.
Be careful not to run the pedal to hot, so as not to burn out the inputs on your soundcard. -Anyway, any good recording software should have peak/level meters.
[I use Magix Music Studio, 16 track DAW software, I scored at Best Buy for ~$20]