Question

Can anyone teach me how to do acid and base? (chemistry)

Answer 1

Acids have a PH level of 6 or lower
Bases have a PH of 8 or higher
PH 7 is neutral

Answer 2

For the topic of conjugate acids and bases you know that the if you have an acid (sometimes labeled as HA), its conjugate base is HA minus one H⁺ ion (sometimes called a proton).  The conjugate base of HCl is Cl₋, the conjugate base of H₂SO₄ is HSO₄⁻, the conjugate base of CH₃COOH is CH₃COO⁻, and so on.  To find the conjugate acid of a base, you have to reverse that process.  The conjugate acid of HCO₃⁻ is H₂CO₃, the conjugate acid of NH₃ is NH₄⁺, the conjugate acid of PO₄³⁻ is HPO₄²⁻, and so on.  

examples:
HCl+H₂O⇒H₃O⁺+Cl⁻
acid=HCl, base=H₂O, conjugate base=Cl⁻, and conjugate acid=H₃O⁺

NH₃+H₂O⇒NH₄⁺+OH⁻
acid=H₂O, base=NH₃, conjugate base=OH⁻, and conjugate acid=NH₄⁺

I hope this helps.  Let me know if anything is unclear or you want me to explain anything further.