A Traditional IRA is limited to $6000 each ($7000 if you are age 50 or older). Whether or not it is deductible or not depends on what your income is (a SEP is an employer plan, so that could limit it){.
https://www.irs.gov/retirement-plans/2019-ira-deduction-limits-effect-of-modified-agi-on-deduction-i...
If you are interested in larger retirement contributions for 2020, you may look into a 401(k) plan.
