What is necessary document that establishes you are eligible for transfer

Para legal team thAT processed successfully my H1B clearly states that I am taken out of the cap limit and am eligible to apply for new employer, though they delimit their words to sound, "I could chose " to work for others Simple questions which help me in going forward are: What is or which is (are) necessary and sufficient document(s) that one must see and look at and show to some one such that henceforth we can freely apply for jobs from other employersWhat are steps to transfer the visa to new employer and who would pay for the same?If a first employer after successfully obtaining you your visa, does not invite you by flight and does not call you to occupy the position, offered, are there some cases as use cases in which case, what options or how can the candidate deal with the situation?; are there any legal obligations such as three month pay that must be paid by the first employer?; what are legal chances to file a case against first employer?; are there any use cases in history? Trust all is well with all of you, these are in no way indicative of my motto of doing anything to any onethese are questions to learn answers from you all Sincere thanksAT Kishore