How can a U.S. citizen sponsor her Indian fiancé for a visa and later a green card?

Hello, My daughter is a U.S. citizen and recently got engaged in India to an Indian citizen. We are seeking guidance on the correct immigration pathway for her fiancé to come to the United States and eventually obtain lawful permanent residency (green card). We would like to understand the available options (fiancé visa vs. marriage-based visa), the step-by-step process, timelines, documentation requirements, and any potential issues to be aware of. We are also interested in knowing when it is appropriate to hire an immigration attorney and what role the attorney would play during the process. Additionally, we plan to conduct the marriage ceremony in the United States, and my daughter would like to invite the groom’s immediate family, including his parents and brother, to attend the wedding. We would appreciate guidance on the appropriate visa options for them, eligibility requirements, and best practices to avoid visa denials. Thank you for your time and guidance.