Not what the nuns taught in my day. But this new RCC any Tom, Dick or Harry will make it into heaven even if they are Muslim, a Buhhdist etc.You can receive baptism in a non-RC church and be reborn and live your life by the Spirit and enter heaven.
You will have met the criteria for receiving the Spirit (believed in your heart), met the criteria for being reborn (become a member in Christ and received a new heart and renewal of the mind from the Spirit), and if you lived by the Spirit met the criteria of producing good fruit to be looked at on the final judgment. More importantly, you will have within you (love) the thing you need in order to see God, who is love.
What you cannot do is to go against your conscience. You cannot, knowing that the Catholic Church is true and the Pope its head, refuse to enter.
But you obviously don't believe the Church is true, so you're not going against conscience.
You don't have to be correct in what you think the Catholic Church teaches. You're not rejecting the Church but your belief as to what the Church is and teaches - and you must never go against your conscience. You would be committing a sin if you did.
The nuns taught us that our consciences could be dulled.
1 Tim 4:2
Such teachings come through hypocritical liars, whose consciences have been seared as with a hot iron.