Pronouns: pronombres
Nouns: sustantivos
First the correction:
Se amo a ella --> La amo a ella (without "se" and with the article "La")
Lo quiero a ir a su casa --> Quiero ir a su casa (Without "Lo")
There're differents types of pronouns (personal, possessive, demonstrative, indefinite, enclitic) and their use depend of differents things. Is really difficult to explain.