file robots and sitemap wp6

HI

I've been dealing with seo for many years but haven't had much experience with wp

I migrated a customer's site and now it's online

but I notice 2 things

1) there is no robots file on the root and as I see the wp core does not provide it, how can I create a valid robot file for wp with woocommerce?

2) when creating an xml sitemap, the various online tools are unable to access and return a system with only one line (the home)

the 2 things seem related... what blocks or what can block the boot of the engines ???

thanks for your support in advance