What type of wood is it? That will determine if it needs a wood conditioner. Stain will not give you a shiny/glossy finish, that would be an exterior grade polyurethane or waterbourne sealer.

It's not like conditioner is required. It's just an optional step that you can use to help get the stain to apply more evenly because it fills in all the deep areas of the grain. If it is car siding, part of the character of the wood is its uneven look. The best way to stain is with a staining pad of synthetic wool because they have handles. You put the stain on and wipe off the excess. After that, you will need at least two coats of some exterior grade finish in satin or semi-gloss depending on your preference for how shiny you like it. You will need to sand in between coats so that the final finish is smooth.