TheHarvester is a great tool to dam harvest everything from a url. You also can use shodan to get alot information about a website/company.

https://tools.kali.org/information-gathering/theharvester

Usage: theharvester options

   -d: Domain to search or company name
   -b: data source: baidu, bing, bingapi, dogpile, google, googleCSE,
                    googleplus, google-profiles, linkedin, pgp, twitter, vhost,
                    virustotal, threatcrowd, crtsh, netcraft, yahoo, all

   -s: start in result number X (default: 0)
   -v: verify host name via dns resolution and search for virtual hosts
   -f: save the results into an HTML and XML file (both)
   -n: perform a DNS reverse query on all ranges discovered
   -c: perform a DNS brute force for the domain name
   -t: perform a DNS TLD expansion discovery
   -e: use this DNS server
   -p: port scan the detected hosts and check for Takeovers (80,443,22,21,8080)
   -l: limit the number of results to work with(bing goes from 50 to 50 results,
        google 100 to 100, and pgp doesn't use this option)
   -h: use SHODAN database to query discovered hosts

Examples: theharvester -d microsoft.com -l 500 -b google -h myresults.html theharvester -d microsoft.com -b pgp theharvester -d microsoft -l 200 -b linkedin theharvester -d apple.com -b googleCSE -l 500 -s 300