Cells not recognizing data as numbers, tried every trick I found online

So I copy and pasted some data into excel. I copied row by row from a pdf into an excel because the converting feature wasn't working well. Now, none of the data is being recognized as numbers except 0's (on left side of cell, can't be used in equations, there isn't an error on the cells but error when trying to use them as numbers). I looked into it and tried all the tricks I could find and the only thing that works is going to individual cells, retyping the numbers and hitting enter but I would love to find an easier way to convert all this data. Here's what I've tried:

1. Hitting enter on the cells

2. Typing and copying 1 and then special paste > multiplying by one

3. Removing space with text to columns

4. Using the value command

I'm not sure if maybe I just don't understand what the issue is, but I need to use the data for a coding assignment and right now my coding software doesn't want the csv because the cells are recognized by numbers. Does anyone know the best way to fix this?