Question: I am unable to go to shul to hear parshas zachor. What should I do?
Answer: The Rosh (Berachos 7:20) writes that reading parshas zachor is a mitzva deoraisa that should be performed with a minyan (See Tosafos Berachos 13a). The Terumas Hadeshen (108) paskens like this, writing that it is more important, therefore, to listen to parshas zachor being read with a minyan than to listen to the megilla with a minyan. The Pri Chadash (OC 146:2) questions why the Rosh maintains the need for a minyan (See Shaar Hatziyun 685:5). The Keren Ora (Berachos 3a) suggests that the mitzva to vanquish Amalek is a communal one and this is why we read parshas zachor as a community.
The Shulchan Aruch (OC 685:7) writes that one who lives in a village with no shul should endeavour to go to a place with a minyan for this Shabbos (See Shulchan Aruch OC 146:2).
The Rema adds that one who is unable to attend should still read it with its correct tune. The Kaf Hachaim (OC 685:35) explains that one should read parshas zachor from a Chumash unless they have a sefer Torah.
In conclusion, it is important for one to try to hear parshas zachor read in Shul. If one is unable to do so, one should read it to themselves from a Chumash, ideally in the right tune.