Your local computer club, church, youth group, U3A, library, charities co-ordinator, local authority (City Hall?) Salvation Army, Sports clubs and the like would be able to steer you in the right direction.
In the UK (khere I'm based) each local authority (City Hall?) has lists of voluntary organisations and often funds these sort of arrangements especially for disadvantaged groups including oldsters and youngsters.
I used to run several computer repair shops and regularly refurbished older " pensioned off" computers and donated them to local good causes... there was always a good demand for them and for folks who just could not afford buying even the cheapest new machine it often was an "antidote" to social isolation, loneliness and the difficulty of keeping in touch with kith and kin often dispersed to all four corners of the world...
It also gives the donor a nice warm feeling!