A bit of forward planning would have helped.
If I'm not wrong then the word 'forward' is an adjective here. Because it's modifying the word 'planning'.let me know, I'm right.
For a start, adjectives don't modify, they qualify (A noun). Adverbs modify, they modify verbs. It's easy to remember if you remind yourself that 'adverb' already includes the word, 'verb'.
The grammatically correct way to describe an adjective is (for example) 'nice' - adjective qualifying the noun, 'day' (in the sentence, 'It was a nice day'). For adverbs, it is (for example), adverb, modifying the verb 'swims' (in the sentence, 'She swims well').
The easiest way to distinguish adjectives from adverbs is to remember that an adjective tells you what 'type' of noun it is (what type of day? - a nice day)), whereas adverbs tell you 'how, when, where or why' something happened (how does she swim? - she swims well).
'Forward' is an adverb, not an adjective, as it indicates a direction or location (ie 'where'), so the use of it as an adjective is ungrammatical, and 'forward planning' is the only example of 'forward' used as an adjective that I am aware of - it has become very popular in business jargon. I'm not averse to the use of words ungrammatically if it gives a new way of looking at something, but the example of 'forward planning' is actually poor English to the point of being comical, as it's a tautology (saying the same thing twice, ie employing superfluous words), because all planning looks 'forward', so adding the word 'forward' doesn't add anything to the phrase. Sorry to be long-winded, but it takes a bit to explain these things which every kid knew by the time they were 10 or 12 when I was young. However, the chaotic approach to teaching English in schools over the past 30-40 years has resulted in recent generations being full of confusion when it comes to making word choices.