It depends on what you are aiming to build.
It is a bit hard to give an exact suggestion, because it really depends a lot on what you would like to build.
In a way it also depends on your disability. e.g. if you have lost one arm it makes little sense to suggest you getting a hand plane that should be used using both hands, but a block plane would make perfectly sense.
Making small boxes or chests can be done with relatively few tools. If you check out Doug Stowes’ blog: wisdomofhands.blogspot.comyou can see some examples of his work.
But to really get down to the basics, a hack saw can be used for making joinery cuts even in wood, so that is a cheap entry way to a saw.
You will probably also need a couple of chisels, say a 1/4″ and a 3/8″ or a 1/2″.
With those tools and the general home owners tools you can go a long way.
Good luck and remember to have fun while pursuing this hobby.