Posting on Instagram is quite straightforward, even for beginners. Start by downloading and opening the Instagram app. Sign up or log in to your account, tap the plus icon at the bottom center of your screen, select a photo or video from your library, then hit Next. You can now choose to apply filters or edit your post. When you're ready, tap Next again, then add a caption, tags, and location if you want, and finally tap Share to post your content.