Will i get more back filing married single if I'm the only one who worked and can claim abandoned and get the EITC?

There is no such thing as "married filing single."    If you were legally married at the end of 2025, your choices are to file a joint return or to file married filing separately.   If you file married filing separately you are not eligible for earned income credit.

If you are legally married at the end of 2025 your filing choices are married filing jointly or married filing separately when you prepare your 2025 return next year.

Married Filing Jointly is usually better, even if one spouse had little or no income. When you file a joint return, you and your spouse will get the married filing jointly standard deduction of $31,500 (+ $1600 for each spouse 65 or older)  for 2025. You are eligible for more credits including education credits, earned income credit, child and dependent care credit, and a larger income limit to receive the child tax credit. 

If you choose to file married filing separately, both spouses have to file the same way—either you both itemize or you both use standard deduction. Your tax rate will be higher than on a joint return.

 Some of the special rules for filing separately include: you cannot get earned income credit, education credits, adoption credits, or deductions for student loan interest. A higher percent of your Social Security benefits may be taxable. In many cases you will not be able to take the child and dependent care credit. The amount you can contribute to a retirement account will be affected. If you live in a community property state, you will be required to provide additional information regarding your spouse’s income. ( Community property states:  AZ, CA, ID, LA, NV, NM, TX, WA, WI)

 If  you are using online TurboTax to prepare your returns, you will need to prepare two separate returns and pay twice since with online, you get one return per fee.

https://turbotax.intuit.com/tax-tips/marriage/should-you-and-your-spouse-file-taxes-jointly-or-separately/L7gyjnqyM?srsltid=AfmBOopGqCNexowW0pYgvsf7ycIkrx4VjO_63UXv6vSnfu3UEGQiKQTh

https://ttlc.intuit.com/turbotax-support/en-us/help-article/income/getting-married-mean-taxes/L2RgmagpE_US_en_US?uid=m69on7t0

You mentioned being abandoned.  Did you live with your spouse at any time during the last six months of the year?

Do you have children that you will be claiming as dependents?

Depending on the answers and other circumstances, it is possible you could qualify for Head of Household and be able to claimed the Earned Income Credit.  But that is a big "maybe", depending on the details.

At any rate, you seem to be asking about how much your refund will be, and the best answer to that is to prepare your tax return and answer all of the questions.