Yes.
You can use a store bought liner.  It is important to carefully read the instructions.
If you are thinking about using an over-the-counter  liner, it is important to speak to your dentist first. This is because over-the-counter denture liners may not be a good fit for your dentures and could cause them to become loose.
Another option is to speak to your dentist about a semi-permanent soft liner.  Soft liners are more comfortable than hard acrylic against your gums.