I want to write a formula or maybe do select expert.

Let's say I have 5 people and each day they get a check or an X. I want to run a report for like the month of December that shows me who all has ALL checks and no X's.

I have a field called employee and I have one called presence. I know that is not much to go on but we had tried a formula that said if any x's then false, but it shows those people on their check's so it doesn't help me.

You would not want to limit the filter on the select(unless every month or ever report it is a set number of how many "checks" there are).
1.) Instead pull all the information, then group it by the {table.employee} field.
2.) Then create a new formula called "CheckorX"
    If {table.presence}="Check" then 0 else 1
3.) Next suppress the Details Section
4.) for the "Group 1 Header" Section suppress formula type:
    if maximum({@CheckorX},{table.employee})=1 then false else true

and that should do it! Format and design how you want each employee showing up(i.e. name, size, employee ID) in the group 1 header instead of the details.