Grad school After TESC

[Paul]

I've searched this site via the search option & have read a lot on here about grad school ect but I'm still comfused. If one starts working on CLEP/DSST exams right after high school (actually a little before graduation) toward a specific goal of say a degree in General Business or Liberal Arts (this is for my son & daughter, not me - I have 59 credits at TAMU from 25 years ago but my priority now is their education ) taking the route of having most of the credits before enrolling in TESC then graduating from TESC, will they be able to go on to a Masters Program if desired since (I guess) one factor in going to grad school is the grade point & the CLEP/DSST is Pass/Fail at TESC? (Forgive my long run-on sentence.) I know all three of the Big Three have their various pluses so I like all three but can anyone set me right on this?
BTW, you guys are great & this is a wonderful site! Thanks for your help!