SCUBA
SCUBA DIVING is DANGEROUS. You cant learn to dive on the internet. These demosntrations and tutorials are for your interest and entertainment only. You need to take a Scuba Diving Course with a qualified professional Scuba Diving instructor at your local dive centre. This professional will be able to guide you through all these skills and the relevant safety theory in a confined and safe environment.
If you would like an assistance in finding an instructor to work with then place leave a message in the comments section and I will do my best to help you find a great instructor near you.