Only with Kanji. Many share the same meaning, and onyomi reading often sounds a little bit like modern mandarin, but the kunyomi readings are exclusively Japanese and you'll have to memorize those separately (Wanikani was helpful for me in this).

For grammar you are out of luck. Japanese is a much more grammar heavy language than Chinese, typically much more complex.

For written Japanese, a lot (for the kanji). For spoken Japanese, it helps with the words that were borrowed from Chinese — and this is a lot, perhaps 50%. But pronunciation is, obviously, recognizable, but differing. For such words (those that consist of characters that are pronounced using the so called on-yomi reading), you're likely to pick on the sound conversion from Chinese to Japanese and vice versa, and at that point make educated guesses to the meaning of those words. That leaves pure Japanese readings of words of course (which includes almost all verbs excluding the nouns that are verbified by suffixing with an inflection of suru), but it helps in the basis.

Knowing Chinese Kanji gives a lot of insight into Japanese Kanji, which is borrowed from Chinese. Some of the meanings are exactly the same