In order to change the homepage meta tags, you simply need to open the "SEO & URLs" page, open the "index" page's settings, and there you can freely edit some important SEO information. 
A few tips: - The default homepage title is the name of the store, and therefore the index' title field is empty. If you put content in the field, the homepage's full title will be "<your content> – <the name of the store>"replaced by your input.
The name of the store itself is set during the installation of PrestaShop, and can be changed from the "Store Contacts" preference page, using the "Shop name" option of the "Contact details" section. - Keep your description short: a paragraph of text is enough.
- To add a meta keyword, click in the "Add tag" field and validate by pressing return. You can remove tags by clicking the cross.
- You do not have to add a rewritten URL if there is already one.
Note that if your store has already been indexed by Google or any other search engine, it might take a while for your changes to appear in the search results. Please be patient. | 
