You probably don't need an XML sitemap at all. They don't do much for SEO. They can help get your URLs discovered and crawled by search engines, but they don't do much to help rankings. The best way to get your pages ranked is to link to them from other pages. If you are linking from other pages, Googlebot can find them without a sitemap. See The Sitemap Paradox.
An XML sitemap can give you additional insight in Google Search Console and it can help Google figure out which of your URLs your prefer when it finds duplicate content. For those reasons, you may still wish to create a sitemap. If you do so, you really only need the
<loc> field. Something like:
<?xml version="1.0" encoding="UTF-8"?>
The other fields are optional and Google ignores them. Google has found that most sites don't use the
changefreq fields appropriately so Google doesn't use those fields from sitemaps at all.
If you add or remove pages from your site you should generate a new XML sitemap. You can just replace the sitemap with a new one so that you don't need to re-submit it. If you don't want to submit them in the first place, you can add them to your robots.txt file with a line like:
You don't need an image sitemap to have your images listed in Google image search. Again Googlebot can crawl your site to find those images.
I believe you do need a sitemap to get your videos listed in Google video search, but I don't have much experience there myself.
You also need a sitemap for listings in Google news if you have news articles on your site. Again, I don't have much experience in that area.