What steps can be taken if I think my lap top has a virus? How do I get rid of nasty pop-ups?

hello, My computer and technological skills are that of a 6 yr. old....No a 4 yr. old When I use my lap top I ONLY use it to email and manage my NETFLIX account. I am an older person and feel proud of myself for learning the very basic computer skills. I have noticed lately that I am getting these awful pop ups even though I have the pop up blocker set to the highest safety level. I also think I may have a virus as I have noticed that the lap top seems slow. Now I do have dial up and I know that can make things slower BUT not this slow. I have no problem continuing to have the dial up feature as I rarely use the computer so a bit slow is fine. What about memory? Is there a way to gain more memory? I have noticed a bit of black will appear on the screen. This has only happened a few times. I have the AVG protection...just the free version but that does not seem to help with the issues. I did attempt to getadditional pd.protection from AVG but that just seemed to make the issues a bit worse.Now to be honest that might have been my fault as I have such little understanding of making changes/repairs. I did contact AVG and got a refund. Now before I take my computer to be repaired are there ANY simple things I could do myself to improve my lap top challenges. Please share responses in a very simple manner that I can follow. Thanks, Karen