How can I make sure that my old user generated content(UGC) is ranking on google ?

My URL: https://safalaya.com . I am using elgg - 1.8.19 . I am recently using Juipo Authentic premium elgg theme . My website has DA 45 . I have more than 100000 blogs,groups etc . as user generated content . How can I make sure that my old user generated content(UGC) is ranking on google ?