In wordpress If you are using Yoast, then there is option with it you can generate sitemap from the plugin. I belive all other plugins too have the same. For non wordpress use this site to generate the sitemap - https://www.xml-sitemaps.com/
In wordpress we have tons of seo plugin that will create the sitemap automatically and add them each time new post or page comes. There are sets of plugins that only helps in generating and refreshing the sitemaps
It is better to utilize the same seo plugin than go for diffrent!. I would tell yoast for wordpress as this is best among all
if you have any CMS system like wordpress etc use plugin and if you have static site use free sitemap creator tool or online sitemap creator tool.
Create an XML sitemap that can be submitted to Google, Bing, Yahoo and other search engines to help them crawl your website better. Then create a Text sitemap to have a plain list of all your pages. After that create a ROR sitemap, which is an independent XML format for any search engine. Finally generate an HTML site map to allow human visitors to easily navigate on your site. Enter you website URL and some information in the prescribed form at xml-sitemaps.com. After that Press 'Start' button and wait until the site is completely crawled. Follow the instructions
Hey Anusha Yoast is good plugin but if you go for pro version and buy extension for video, local etc it is more useful than the general one