Help Please! Main Navigation

Hello lovely people, I'm not very techy so apols if this is a stupid question. On the main navigation on my website (for example the bit in the top right that would say - about us, meet the team, treatments, contact etc) I am using links as the pages don't automatically appear on the navigation. This is fine but I have terrible SEO on google with this site and wonder if this could be a reason why as the rest of the homepage is just a picture really. Am I doing something wrong. Also - one of them says HOME but can I get rid of this as if you press on the logo it goes to Home anyway? And - I appear to have two home pages - the one at the top of the menu tree in Primary Navigation (in the dashboard - Pages), and then one underneath. But if I delete the one underneath then the picture disappears and the website goes funny. Again - is this ok, or is this bad! Thank you in advance!