My filing status is married filing jointly. If I want to
convert my traditional IRA to Roth, do I only consider my IRA funds, or do I need to include my spouse's too? Also, do
I need to include 401(k) funds?

You can only convert your IRAs, or only your wife's, or both, or neither. You can also convert part of any IRA. You cannot directly convert a 401k account.