Pronouns can take the suffix -们 men0 ‘PL’ to indicate plurality. Other than that, plurality can be represented by relevant numerals and classifiers in a nominal phrases, for example, 三 只狗san1 zhi1 gou3 ‘three dogs’.
Shi, Dingxu. 2016. Nouns and nominal phrases. In A Reference Grammar of Chinese, eds. by Chu-Ren Huang and Dingxu Shi. Cambridge University Press.