If that Class A address block does not belong to you, you CANNOT connect to the Internet with it. But you can use a private IP Class A address block (see RFC 1918), and then connect a NAT between your net and the Internet.
I'm pretty sure that the IANA is NOT assigning anyone Class A nets anymore.
Seeing as how most networking people dropped "Class" A, B, C, D and E designations after RFC1517, RFC1518 and RFC1519 came out over 16 years ago... never mind that IANA isn't assigning blocks to anyone other than the five Regional Internet Registries (AfriNIC, APNIC, ARIN, LACNIC and RIPE), yeah that's reasonable.
If you look at recent allocation data, the five RIR have become a lot tighter handing out chunks of IPv4 space. I don't have actual stats handy, but the visual impression of viewing the monthly differences show a lot more new blocks at and below a /20, with a high incidence of /24s (former 'Class C') chunks.
Never - they don't have those /8s. 184.108.40.206/8 is assigned/allocated to more than 10 different companies in six countries (.ar, .bs, .ca, .nl, .pr and .us). 220.127.116.11/8 is assigned/allocated to more than a dozen companies and seven countries (.bb, .bs, .ca, .jm, .pr, .tc and .us). 18.104.22.168/8 is similarly fragmented, but only five countries (.ag, .bm, .ca, .pr and .us). The URL
might be useful.
Technology. Try "what is a switch" compared to "what is a hub". Same concepts.