You have to know what you're doing first for ANY virtual design

The computer doesn't know your room size, your tastes, the effect or feel you want.

You have to crawl before you run

Collect inspo pics of what you like

measure all the rooms, plan furniture needs. seating accent , case pieces to scale

There are professional design services/virtual only

I wouldn't recommend the method.

Want to go it alone?

https://www.spoak.com/design-tools?utm_source=google&utm_medium=cpc&utm_campaign=17335446191&utm_content=140047870707&utm_term=design%20your%20own%20room%20app&utm_source=google&utm_medium=search&utm_campaign=_&utm_term=design%20your%20own%20room%20app&utm_content=600107182442&gclid=Cj0KCQiAvqGcBhCJARIsAFQ5ke6BSkC0TVM_gYUx3ufbVil1U2JUawxcGtFUKFX8P9cuh72MvhxkuycaAsPPEALw_wcB

You could use Photoshop, It is a great program but it is expensive and has a steep learning curve.

I often use MS Paint. It is free on most PC's and is much easier than Photoshop to get the hang of but you kind of have to figure it out on your own. The best way is just to play around with the program. You could probably find some YT videos that show you some basics as well. Paint is more than enough to get a basic idea of how a photo of a wallpaper, sofa, or chandelier found on the internet is going to look in a space. It is easiest to use if all the photos are straight and you are not trying to position anything on an angle.