Can I use toothpaste for my acne?

Yes, drys it out ;.. Toothpaste and most other neutral ph. "clean" drying agents can "treat" the symptoms of acne just like many otc acne treatments. Also, it is possible that the antibacterial agent triclosan found only in colgate total may an additional minor therapeutic value as well.
Not for Acne. That is an old tale. I can cause irritation and possible infection. Try otc meds for acne and, if necessary, a dermatologist.
For your teeth. Use products specifically formulated for acne treatment... Toothpaste is not formulated to treat acne.