Do you have a title for it? The VIN is usually stamped on the tongue, sometimes very hard to locate. I think someone said they found it on the bottom of the tongue and some on the side. Also, the VIN is sometimes on a decal inside one of the interior cabinets. Hi-Lo uses the length and the year as their model numbers. Like my trailer is a 24' made in 2004, so it's a 2404T. The owners manuals are pretty generic between the years. Here is the link to the owners manuals that are in the site reference library. Just find one that's close to your year and it should help.
Hi-Lo Owners Manual - Hi-Lo camper travel trailer forum
Here is the link to the brochures.
Hi-Lo Brochure - Hi-Lo camper travel trailer forum
Hope this helps you get started. The forum members are pretty experienced so any questions you may have, please post them on the forum and you will get tons of help.