For the background itself, a real one beats a virtual one in almost every case. Virtual backgrounds have visible edges, particularly around hair and hands, and they distract from what you are saying. A plain wall with something small and deliberate in shot, such as a shelf or a plant, reads as professional without effort. The bar is lower than people assume: the goal is that nothing pulls attention, not that it looks like a studio.
Position the camera at eye level rather than below it, which is what happens by default with a laptop on a desk. Looking up at somebody is unflattering and reads as less confident, and the fix is a stack of books. Sit far enough back that your head and shoulders fill the frame rather than your face alone, and leave a small amount of space above your head.
Sound is the thing viewers actually judge and the thing most people neglect. A laptop microphone in a room with hard surfaces produces an echo that makes concentration tiring, and viewers will tolerate mediocre picture far longer than poor audio. Any inexpensive external microphone, or even wired earphones with a microphone, is a substantial improvement over the built in one.
Once it is set up, leave it. The value of a fixed arrangement is that it requires no decisions before a call, which is exactly when you have no attention for it.
Test the whole arrangement by recording two minutes of yourself talking and watching it back before a call that matters. It is uncomfortable and it reveals things you cannot notice while in the call: that the light is unflattering from one side, that a reflection appears in your glasses, that the microphone picks up an air conditioner you had stopped hearing. Fixing those takes minutes once identified and they are otherwise invisible to you and obvious to everybody else. Keep a spare pair of wired earphones within reach as well, since they are a reliable fallback when a wireless microphone fails partway through a call and nobody can hear you.