Can't install ladspa plugins in Audacity with Ubuntu

Hi there, hope someone can help. I've just installed ubuntu, after using Linux Mint for a few years and I'm having problems installing the ladspa or LV2 plugins for audacity. With mint, I just got them from the repository but can't see to find them in Ubuntu. Is it a different repository? I did download them, but can't move them to the correct audacity folder as I seem to remember doing in Windows, as it just keeps saying that it's a read only folder - and when I try to change that it says I can't change the permissions as I'm not the owner...... Can anyone help please? Thank you David