As bio says . It will self prime but it takes some power and time to do it so give it a little help and fill the filter then bleed it of with the lift pump and you should be good to go ....
...however , as JG says , if it it is not truly bone dry then it should be a case of fuel up and try it . So if doesnt fire up straight away then go to the above .
This fuel theft thing is getting common , down here its happening to peoples heating oil . A lot of houses run on it as we dont have much of a piped gas network . You go out to work and come home to a cold house and an empty tank . Considering it can cost 750 to 1k to fill a tank, thats a lot of theft . Obviously transport yards are getting hit and there are few farms that havent had some kind of incursion by undesireables .
The last time I remember widespread theft of fuel from cars was in the thatcher years . I recall a bit of an outburst in the early 90s but nothing like as widespread as now .
I am sincerely sorry to hear that this has happened to you .