Something alternative to simple sitemaps


so I tried using this plugin and well it kinda crashed my site luckily I was able to get it back up so now back to my question can anyone suggest good alternative for that?

What im trying to get to work is when I google my site “moleskinestore” it shows up in the search result but under the link it says “A description for this result is not available because of this site’s robots.txt” and I read somewhere that to fix it I need xml sitemap anyone could help me get the actual description while googling?