Consult in private with an immigration attorney on how to go about this

It depends on your country of nationality. I suggest you with an immigration attorney.

You may file as soon as you are married but your chance of success depends upon, among other things, the sufficiency of proof of bona fide marital...

Form I-864. I suggest you work with an attorney.

It depends on his country of nationality. I suggest you work with an immigration attorney

Submit strong evidence of non-immigrant intent.

There is usually just one biometrics appointment for I-485, I-765, and I-131

If you travel to your home country, you need to apply for an H1B visa stamp on your passport in order to be admitted on H1B

If your J1 is subject to INA 212e, you may need to fulfill a 2-year home residency before changing to another immigration status. I suggest you...

2 years and 9 months from receiving your green card if you are married to a US citizen