I want to paint my RV cabinets. I’m not sure what they are made of. I bought Valspar signature. Will this work? If so, what prep is necessary?

We would need to determine the material your cabinets are made from, but typically this would work. RECOMMENDED USES: Properly prepared interior walls and ceilings including previously painted and primed plaster, wood, brick, drywall, cement and metal. General Prep: Read the Lead Warning paragraph. Thoroughly clean the surface and allow to dry. Remove wallpaper and loose, peeling paint. Remove gloss from shiny surfaces. Patch cracks and spot prime. Valspar Signature® paint can be used to prime patched areas and bare surfaces before applying the finish coat. For best results on heavily stained areas, drastic color changes or deep, vivid colors, prime with Valspar® Interior Multi-Purpose PrimerSealer for optimal color accuracy and coverage.