when use tari, use the following formula
V.a tari + V.b Tari simasu
do Verb.a and Verb.b and other...
for example
本を読んだり、テレビを見たりします
hon wo yondari, terebi wo mitari
reading a book and watching TV
カラオケをしたり、買い物したりします
karaoke wo sitari, kaimonositari simasu
doing karaoke, and shopping
this expression is used when listing up two or three of variety things that one does.
here other example
子供のごろ 毎日 公園で あそびたり 歌をうたりします
kodomono goro mainichi kouen de asobitari utawoutari shimasu
when (i) child everyday i playing in ground, and singing a song.