Doubt regarding dataset

I wanted to get an idea about how much percentage of value is ok in the analysis like what percentage of null values or missing values should we assume in the case study and proceed if we take the analysis by approaching with dropping columns/rows having more than 30% null values or blanks or missing values than much of the data will be lost but then handling the columns using descriptive stats will alter the overall analysis a lot so wanted to get a hint of what would be the ideal percentage for treatment of cleaning a rough percentage or range would help me to clean the data and remove the unnecessary columns a bit more faster as in the dataset or description nothing is mentioned about the same.ideally in data cleaning methods if we have large dataset we are given some threshold to follow dropping the entries or to impute them so can you help me a bit with the range to take into consideration.