Excel functions that you ACTUALLY need

 Text Functions 

LEFT,RIGHT AND MID: These functions help extract specific parts of text from a cell . For instance, if you have a dataset with full names in a single column, you can use these functions to separate first and last names into different columns.

TRIM: This function removes extra spaces from a text string.

UPPER,LOWER AND PROPER: These functions convert text to uppercase, lowercase, or proper case(proper case being where the first letter is capitalized, and the rest are in lowercase). This can be helpful when dealing with data that has inconsistent capitalization.

Lookup Functions

Lookup functions help you find and retrieve data from other parts of the worksheet or other worksheets based on specific criteria. 

VLOOKUP AND HLOOKUP:These functions search for a value in the first column or row of a table and return a corresponding value from another column or row. They're useful for merging data from multiple sources or filling in missing data.

INDEX AND MATCH: These functions can be combined to perform more flexible lookups than VLOOKUP and HLOOKUP. They're especially useful when the lookup value is not in first row or column of the table or when you need to perform a two-way lookup. 

Date and Time Functions

Date, Time and Datevalue: These functions help you create date or time values and convert text strings into date or time formats. This is particularly useful when importing data from external sources that may have different date or time formats.

Year, Month and Day: These functions extract the year, month, or day from a date value. They can be useful for grouping data by specific time periods.

Logical Functions

If: This function tests a condition and returns one value if the condition is true and another value if it is false. For example, you can use the IF function to categorize sales amounts as ḧigh" or "low" based on a threshold value.

Countif and Sumif: These functions count or sum the values in a range that meet a specified condition. They're useful for aggregating data based on a specific criteria.

Data validation and Conditional Formatting

Data validation: This tool allows you to set criteria for the allowable data in a cell or range of cells. For example, you can restrict the input to numbers within a specific range, dates within a specific period, or a list of predefined options. Data validation can help you prevent errors and inconsistencies in your data.

Conditional Formatting: With this feature, you can apply different formats(such as colors, fonts, or icons) to cells based on specific conditions. Conditional formatting can help you quickly spot errors, outliers, or patterns in your data.