I would encourage you to do so. I do not think it would be wrong to learn how to use a common Open Source program like this. If you watch lot of YouTube, there is a channel Davies Media Design that teaches a lot of stuff in GIMP:
- YouTube directly: https://www.youtube.com/channel/UCq79-lfj2w7oRXGRcOP2B7g
- or through Invidious (an anonymized YouTube client in the browser): https://invidious.nerdvpn.de/channel/UCq79-lfj2w7oRXGRcOP2B7g
The major ones are already listed, so I mention only a few lesser known ones: