I've read on the Internet about people who are some distance from an Orthodox church. I've often wondered if I had been too far from an Orthodox church if I'd have become Catholic. I'm not sure I could accept the infallibility of the Pope. I do accept him as the first among equals. (First among equals is the current Orthodox understanding where the Pope has more honor than the other patriarchs, but he doesn't have more authority.)
Could I have become Catholic if I understand the Pope as the first among equals?
The Catholic Church doesn't say "The Pope is infallible", but rather "The Pope is infallible whenever he makes an ex cathedra
(If you want to read the precise statement from Vatican I, it is: "When the Roman Pontiff speaks ex cathedra, that is, when in exercising his office as shepherd and teacher of all Christians he defines with his supreme apostolic authority that a doctrine on faith and morals is to be held by the whole Church, through the divine assistance promised him in the person of St. Peter, he enjoys that infallibility with which the divine Redeemer wished to endow his Church in defining a doctrine on faith and morals.)
As far as whether Catholics are required to believe that, the answer is yes. But
I would like to stress that there is no official list of ex cathedra
statements -- thus a Catholic is not required to believe, e.g., that the pope made an ex cathedra
statement in 1854 when he defined the Immaculate Conception. (Note, however, that your typical Catholic does consider that to be an ex cathedra
statement and, I should warn you, more often than not he or she also assumes that everyone else does too and might therefore look at you like you have three or four heads if you suggest otherwise.
Personally, I tend to keep my opinions about "How many ex cathedra
statements have their been?" to myself when in conversation with my fellow Catholics, unless I know that they are pretty well educated about such things.)