If you only get ssi or SS or SSDI it is not taxable and you do not have to file a return. And there is no benefit in claiming dependents or deductions. Unless you have federal income taxes withheld from the benefits or you get health care insurance through one of the state marketplace exchanges and receive a Form 1095-A then you need to file a tax return.
If you need to file i have links to the blank IRS forms for the years. Like here are some blank forms & instructions for 2014
1040 https://www.irs.gov/pub/irs-prior/f1040--2014.pdf
Instructions https://www.irs.gov/pub/irs-prior/i1040gi--2014.pdf
1040A https://www.irs.gov/pub/irs-prior/f1040a--2014.pdf
Instructions https://www.irs.gov/pub/irs-prior/i1040a--2014.pdf
1040EZ https://www.irs.gov/pub/irs-prior/f1040ez--2014.pdf
Instructions https://www.irs.gov/pub/irs-prior/i1040ez--2014.pdf
2014 Tax Tables https://www.irs.gov/pub/irs-prior/i1040tt--2014.pdf
Publication 17 Tax Guide for 2014 https://www.irs.gov/pub/irs-prior/p17--2014.pdf
