How do i know if i can contribute to an IRA, Roth IRA or not based on last years income?

Any contribution you make to an IRA, Traditional or Roth, after May 17, 2021 is based on your 2021 taxable compensation, not 2020.

IRS website for deduction limits - https://www.irs.gov/retirement-plans/ira-deduction-limits

IRS website for contribution limits - https://www.irs.gov/retirement-plans/plan-participant-employee/retirement-topics-ira-contribution-limits

Although there is a provision, under covid rules,  to base your Earned Income Credit (for 2020) on the previous year's earned income; I'm not aware of any similar provision for IRA contributions.  

Your current year contribution must be based on your current year "compensation" (generally, your earned income).