I strongly recommend Krita for Graphics as it is very powerful and free to use. Also, for editing sound effects and/or making and editing music, Reaper is practically a free DAW (Digital Audio Workstation) - it has an unlimited - both in time and functionality - demo version. It prompts you with a “This is a Demo” but other than that, it’s free. And once you make it, you can donate
Also, Affinity Designer for vector graphics. It’s not free, but it’s much cheaper than Illustrator and almost as poweful (lacking proprtional tools, warping and power duplication, but other than that, it’s golden.