Does paper acceptance mean an on-site talk is required? I am sorry for naïveté. 

I found a workshop that fits my research and I want to submit a paper to the workshop. The problem is that the location of the workshop is far away from my hometown and I don't have funding to cover the travel expenses.

Do you think it is obligatory to visit the workshop (conference) and to give a talk in case the paper is accepted?
Personally, I have only seen conferences which require every paper to be presented on-site. Most conferences explicitely state that paper will not be published in the online proceedings, if the authors do not present their paper. If this is not stated on the conference's website, please write to the committee.

However, I recommend you to find a different solution. Discussing a paper at a conference is a very important part of your scientific career since you get in contact with other researchers. If you encounter financial difficulties, you can write to the committee and ask politely for a waiver or reduction of the fee.