Unfortunately, spam is a major problem for all websites, especially those using Wordpress. If you are administering your own Wordpress website on a server, you may want to look at the Wordpress.org "Combatting Comment Spam" page. If you are using free hosting from Wordpress.com, take a look at the Wordpress.com "Manage Comments" page.
If you are using a Wordpress site but are not an administrator, you have a few options:
If you're a part of a larger class website (in other words, other people can log into the website), you can go to the Dashboard, hover over "Settings" and then click "Discussion." There you'll see an option for "Users must be registered and logged in to comment" - check that and save. This will allow people who are logged in to comment, but will not allow spammers. If you select this option, you may want to also look at the "Before a comment appears" section and uncheck both - if login is required, you probably will need to moderate comments (although you may still wish to do so).
If you are the only person who can log in to your site, your options are probably limited to either filtering through spam or turning off comments by going to the Dashboard, hovering over "Settings" and then clicking "Discussion." From there, you can uncheck "Allow people to post comments on new articles." and remove the comment option from all future posts. If you want to remove comments from all posts you've already made, click "Posts," then select them all, click "Edit" under bulk actions, hit apply for "Do not Allow" next to comments, and then update posts.