In short, foreplay covers any activity leading up to, getting ready for, having sex with someone. This might be almost anything: talking, flirting, dancing, kissing, stroking, massage or more intimate contact.
Opinions vary as to where foreplay ends and sex begins – for example, some people might call oral sex foreplay if it is followed by something else. Others would say it is definitely “sex” but, ultimately, it doesn’t really matter what you call it – it’s more important to focus on what you and your partner enjoy than what label to put on it.
But be willing to try slowly building up to sex – it can make an enormous difference to how enjoyable the experience is. As long as your are happy, consenting and communicating with each other, then experimenting is a good thing 🙂