Difference between plugin and script?

Hi

I’m looking to create a section on my existing wordpress site for a dating site. It won’t be a standalone dating site, but one incorporated into an existing directory site.

I’m struggling to find a plugin which is affordable or open plan to do the job. I’ve been looking at scripts instead, but how do these alter from plugins? I’ve never added a script onto an existing wordpress website. Is it a wise thing to do?

I really want an all one one solution if possible. I’m not good with coding and don’t have much funding to get this up and running.

Thanks