Ubuntu 16.04 16GB RAM.
About the amount of swap you need, see this discussion: I have 16GB RAM. Do I need 32GB swap? It highly depends on your usage of the machine.
About how to increase swap memory: you can use GParted and see from there if you have some unallocated partition that you can use. If this is not the case, you can also use a swap file. See here for details: How to increase swap space?