I'd say go for CTFs. They are the best way to learn. Also you can download boxes from VulnHub which you can hack. About learning specific attacks you can just p

I'd say go for CTFs. They are the best way to learn. Also you can download boxes from VulnHub which you can hack. About learning specific attacks you can just pick any book from that list and you'll be good to go. My only advice is to be persistent.