Can anyone tell me or lead me to a good video to clean up the bubbles in background?
What font is that? It looks like it has a rustic appearance, where the letters themselves aren’t completely filled. My assumption is you need to open the graphic in Photoshop or your preferred graphic editing software and zoom in on those bubbles and make sure they are painted the same color as the area around it.
If you could share the graphic, or even crop a couple letters and share the cropped region of the graphic, it might help diagnose the problem if the above isn’t correct.
As an example, here’s a font that I suspect is similar to yours (with the holes in the lettering).
Mark Lindsay on YT. He has a video on bitmap clean up. And he also has one on node editing and clean up. might be in the same video.
Do you need to clean it up? Just don’t cut the bubbles in the pocket if you don’t want them.