Hindi, Nepali, Marathi, and Sanskrit are all written with the Hindi alphabet, also known as the Devanagari script. There are no distinct letter cases. It is written left to right, hanging from the printed lines rather than sitting on them. It is good to practice writing these as you learn to read them, even if you won't ever need to be able to write it. There is some variation between written and typed characters, but this is minimal and can be ignored if writing isn't a required skill for you.
If you want to be able to communicate well in Hindi, you have to speak with correct pronunciation. Before you start learning the script, you need to forget (almost) all the sounds you know how to make with your mouth, and be prepared to learn a whole new set of phonemes. If you don't, people will struggle to understand you. And if you try to speak at the pace a native speaker, they will not understand you. They will assume you are speaking English (or your native language), since you are speaking with unfamiliar phonemes.
You need to be prepared to learn some new terminology along the way. You can click on any word with a dotted underline to learn more about that term. Start by familiarizing yourself with these terms.
Place of articulation