You will easily be able to prove meeting, eligibilty to marry and consent forms needed to pass the USCIS stage of this process
the interview will be other issue
CO will look at totality of circumstances (your income needed to support the immigrant, your ability to buy health care insurance for immigrant, your ability to afford the over $2000 needed to adjust his status once in the USA)
all this is very important and need guidance at the interview stage /definetly a joint sponsor
but understand a joint sponsor is only responsible to the government if immigrant becomes a public charge/ u still need to show u can support this person for the year+/- it takes before he can work in the US
https://www.uscis.gov/policy-manual/volume-8-part-g-chapter-4#:~:text=Evaluating whether an applicant is,Immigration Medical Examination and Vaccination
Evaluating whether an applicant is likely at any time to become a public charge based on the totality of the applicant’s circumstances[6] means evaluating all the information provided on the Application to Register Permanent Residence or Adjust Status (Form I-485), Report of Immigration Medical Examination and Vaccination Record (Form I-693), any other forms and evidence contained in the record, and statements by an applicant during an interview, if applicable. USCIS considers all information or evidence in the record that is relevant in the totality of the circumstances.[7]
For all applicants subject to the public charge ground of inadmissibility,[8] the officer will consider the statutory minimum factors: age;[9] health;[10] family status;[11] assets, resources, and financial status;[12] and education and skills.[13] The officer will favorably consider a sufficient Affidavit of Support Under Section 213A of the INA (Form I-864) (when required).[14] The officer will also consider any current or past receipt (or both) of public cash assistance for income maintenance or long-term institutionalization at government expense by the applicant.[15] However, relatively few applicants will be both subject to the public charge ground of inadmissibility and eligible for public benefits prior to adjustment of status.[16]
the very best to the 2 of you and your young love