You earn commission on anybody’s purchase, except yours, if they use your referral link within 24 hours. One tip here is that you can trade referral links with family members and friends and use their link to make your own purchases and ask them to do the same so there can be sharing of the spoils. This might not be the major way to make money in the affiliate program Amazon runs, but it can help your commission structure.
You can use social media to share your blog content with affiliate links, or you can directly share your affiliate links. Note, that you should give an indication that the link is an affiliate link when you post to be transparent and not annoy your followers. People don't want to be sold to all the time, so posting affiliate links should be interspersed with non-affiliate and non-sales posts.