It’s preferable for the bread and wine to be used in the celebration of the mass to be presented by the faithful in procession at the offertory as this fits with the idea of the people of God giving back what He has given to them - fruit of the earth and fruit of the vine. Historically, the bread and wine would actually come from people’s homes / farms.
However this isn’t actually essential, the General Instruction on the Roman Missal (GIRM) states that the bread and wine can be prepared on the credence table in advance of mass if they are not to be presented in the offertory procession. There should nonetheless still be an offertory of some sort as an expression of the participation of the faithful (although the GIRM simply refers to this as being “appropriate” and it’s sometimes skipped when time is limited, for example at lunchtime masses). The GIRM envisages though that the wine and water will be poured into the chalice during mass (and not before) and certainly, the pouring of water into the wine (along with the prayer that accompanies it: “the the mystery of this water and wine may we come to share in the divinity of Christ who humbled himself to share in our humanity”) is intimately linked to the divine act which follows at consecration.
When it comes the the washing of the priest’s hands, again the GIRM envisages (poured) water being used for this since this sort of harks back to Jewish purification rituals with the reference to Psalm 50 in the prayer (“wash me O lord from my iniquity and cleanse me from my sin”) . In the Eastern rites this is done at the beginning as part of the vesting but again water is still used. I’m not sure hand santiser carries the same symbolic meaning and really don’t see any reason why water couldn’t be used (personally I’m using both at the moment). Curiously, the GIRM says nothing about the priest drying his hands…
Finally, the purification of the vessels can take place at the altar or the credence table and this can be done either immediately following the distribution of communion or after mass.