Do you mean you want a job as a band director at a high school?
No. In England marching bands are not part of the school programs. They are independent organizations, kind of like youth bands and drum corps are over here in the U.S.
I would suggest first find people that would like to help and create a committee and divide the work load. Funding will have to be found and lots of local officials informed of your intentions. Instructors need to volunteer or be contracted. Rehearsal locations lined up and publicity created and distributed. Then recruiting members can begin.... maybe with a public open house event.
I remember doing all this and more back when I started the Sound Machine Youth Band in 1984.