vqmod 2.5.0 not working in admin

We have vqmod 2.5.0 in opencart, its not displaying any modules in admin. I want a file upload module to upload pdfs in admin...I have tried many upload modules but none of them work...one File Manger in admin said "permission denied" other said go to "Extension->Extension installer"..I don't see these options in admin...I have been trying this for days now. Any help is greatly appreciated