Hi Kim, I have some good news and some bad news
The bad news is that yes, you do need to be able to access and edit the code on your website in order to implement meta tags. They go in between the <head> and </head> tags in HTML and that's the only way to get them in there. You'll want to add them to each page, once you know how.
The good news is that meta tags are at this point considered a small aspect of on-site
SEO, with the most important elements being on-site content (the text on your page) and relatively keyword density. There are other on-site elements that go into
SEO as well but content really is half the battle. Bearing in mind this is all based on my own experience optimizing my own sites and client sites - there are numerous schools of thought on
SEO and how it all works - some people may swear by meta tags. We do use them on all sites without exception because every little bit helps.
Meta tags basically help tell the search engines what an individual web page is about. It is a short descriptive that sums up the content of a single page.
The Meta tags for any page would look something like this:
<meta name="title" content="
This is the TITLE of your page, it shows up at the tip top of the browser window">
<meta name="keywords" content="
these, are, your, keywords, separated, by, commas, don't, list, a, zillion, of them, just, enough">
<meta name="description" content="
This is what shows up in the search results for any given page - it is best as a full sentence, clearly referencing the content of that particular page.">
When someone queries Google for something relative to the info in the meta tags and/or content the page may or may not pop up in early search results, depending on how strong any other pages on other domains with similar Meta tags may be - it's more likely to rank higher in search results if the content also includes the same keywords being entered by the querent.
Of all these three tags listed above, the description is the most important, followed by the title. The keywords - not so much. Good descriptions can make a huge difference in how people interact with your result once it does pop up on the page.
For example:
search Google for COACH HANDBAGS
Look at and compare the listings on that page for Macy's and eBay:
COACH - Macy's
Coach products at Macys.com. ... SIGNATURE STRIPE HANDBAGS. back to top ... $458.00. COACH ERGO PATENT LEATHER PLEATED FRAME SATCHEL ...
coach, Women's Accessories, Handbags, Women's Shoes items on eBay.com
Buy coach, Women's Accessories, Handbags items on eBay. Find a huge selection of Women's Shoes, Pet Supplies items and get what you want now!
The parts I've highlighted in RED are the 'description' tags. Note that Macy's basically doesn't have any so Google has to fish the content of the page and comes up with a big mess. Ebay's description tags are more carefully installed to inspire people to click through (although, were it my site I'd make them more topic-focused...if I'm shopping for a Coach bag I don't need to see "pet supplies" etc..)
I hope that helps! Let me know if I just confused you more