Does this mean everytime I make a site for someone I have to make a licence with it?
Obviously if you are doing things freelance you need to specify things in the contract. If the client owns your work then the license will be up to the client since your client would own the copyright to your work. If you want to keep the copyright, then contract should have such a clause, and you would need to agree on a suitable license with your client.
Generally, as I understand it, most of the common open-source licenses simply require that any software distribution which includes that software must, as part of the containing software's distribution, include the license and a copy of the unaltered source code of that included software (or in some cases it may be sufficient to make that source code easily available on-line). It does not necessarily put any restrictions on how you license your own code.
According to a popular interpretation, the most common open source license (the GNU GPL) does require one to license one's own software under the same license, even if the license covers a framework/library used by one's own software. That interpretation may or may not hold true, but people tend to assume it does, just to play safe without hiring a lawyer. Then on the other end of the spectrum, some interpretations of other open source license say that you can license your code under a proprietary license, and possibly even license a derivative work of the external software under a proprietary license.
If you have any doubts, you can start by asking the provider of the 3rd party software you are using (and keep a record of their response!).
Their response may not matter though (but at least they would be less likely to sue you if you follow their interpretation), since a court would more likely just interpret the license, not the licensor's interpretation of the license. Of course, I am not a lawyer, and this is not legal opinion.
