Yes you can, sometimes it is refered to as mixing, but it is the same as dissolution: Ethanol in water, octane in petrol, ether in aceton
If they are immiscable, they can not mutually dissolve - think of oil and water. You can shake them up to make an emulsion, but they will then separate unless you have some kind of binding agent to...
yes they can but it depends on the liquids
Water and oil.
Napthalene