Congrats on your decision to enter RCIA.
First, I recall hearing Fr. Benedict Groeschel talking about Jewish people stopping in to use the Sacrament, even though he could not give sacramental absolution. He explained that, but left it open for them to say what they wanted. You may want to double check with an apologist, but I believe that you can enter the confessional, explain that you are not yet Catholic and understand you cannot yet receive sacramental absolution, but would like to confess nonetheless, and would like a blessing.
Secondly, if you should die before you are fully received into the Church, and before you can make a good general confession, God knows your desire. As much mercy as I can have on your plight, imagine how much more that God can have on you. Being that he is God, we can consider his mercy in such circumstances.
I would think that because one can be baptized by desire, that catechumens can be saved should they die before they fully receive baptism, confession, and Communion…
Yet Christians have also always realized that the necessity of water baptism is a
normative rather than an
absolute necessity. There are exceptions to water baptism: It is possible to be saved through “baptism of blood,” martyrdom for Christ, or through “baptism of desire”, that is, an explicit or even implicit desire for baptism.
Thus the
Catechism of the Catholic Church states: “Those who die for the faith, those who are catechumens, and all those who, without knowing of the Church but acting under the inspiration of grace, seek God sincerely and strive to fulfill his will, are saved even if they have not been baptized” (CCC 1281; the salvation of unbaptized infants is also possible under this system; cf. CCC 1260–1, 1283).
Source:
The Necessity of Baptism