document.getElementById('send-data').addEventListener('click',buttonFunction)
function buttonFunction(){

let enteredValue = document.getElementById('entered_value').value
let enteredValue2 = document.getElementById('entered_valuetwo').value
let selectValue = document.getElementById('selected_value').value

console.log(enteredValue,enteredValue2,selectValue)

}

<input id="entered_value" type="number" name="entered_value">
<input id="entered_valuetwo" type="text" name="entered_valuetwo">
<select id="selected_value" name="selected_value"> <option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
</select>
<button type="button" id="send-data">Click me</button>