hey Amit, as someone who has an interest in art and designing and is an self-taught artist myself, my advice would be to not invest in any courses but rather in tools itself like Photoshop, Adobe Illustrator, InDesign, etc if you haven't. There's already a lot of educational content present on Youtube and other social media platforms.
And if you already have those tools, I would still recommend not going for any courses just yet..though it totally depends on your learning preference and also your need, for example, if you want to pursue graphic designing as a professional career, then courses may make more sense..