What are ‘normal’ circumstances? Does a normal person sin? How often? How often would they commit ‘mortal’ sins (the serious ones, ‘sin unto death’ as John puts it as opposed to sin which is ‘not unto death’) and thus, in Catholic theology, ordinarily need the sacrament of Confession?
Certainly there are things Catholics would agree that one needs to do - first and foremost is grace and faith though!
In terms of required belief, the Apostles and Nicene Creeds lay out the miniumum, and the belief in ‘one Holy Catholic and Apostolic Church’ necessarily means belief in all the dogmas that She proposes to the faithful.
Then there are the sacraments (as many of them as are available to the individual, of course), the ten commandments, the two great commandments, the precepts of the Church.
Catholicism, though, when one boils down to it, is not a religion of bare minimums, not in the slightest, but about maximising grace and virtue, and knowledge of God, for the benefit of all and not just the salvation of one’s own soul. So to a Catholic it is an odd question to ask ‘what is the bare minimum that one must do’ but rather 'what are the things that one CAN do to maximise God’s grace and virtue in my life and the lives of others, and how many of ‘em can I get around to doing!’