I have posts that I am sure my friends don't want to see, how can I still get them but be the only one to see them.
Do you mean posts from OTHER people that show up in your newsfeed? Your friends never see those, those only show up to you. If you meant your OWN status posts that you don't want SOME people to see? Then you can control who does or doesn't see those on a post by post basis, there's a little arrow drop-down button that you can click on and select who does or doesn't see it.
Adding to what Artera said, be aware of the posts that you "Like" though, because whenever you Like someone's post it shows up in YOUR own newsfeed that your friends will see (unless they have you set in their own preferences to no be seen in their newsfeed). And of course the same goes for any post by others that you specifically "Share", in which case you can manually select who see's it as you would your own normal posts.