The most common Dutch football cheer is 'Hup Holland Hup' (or 'Hup Oranje Hup'), often followed by a rhythmic clap. 'Kom op' (come on) and 'Ga oranje' (go orange) are also used, but 'Hup' is the classic, all-purpose shout. You can use any of these, but 'Hup' is the most authentic and versatile.
To cheer effectively, match your shout to the situation. 'Hup' works for general encouragement, like when a player is about to take a shot. 'Kom op' is better for urging a player to try harder or recover from a mistake. 'Ga oranje' is a team-specific chant, especially during international matches. The 'links/rechts' song you mentioned is a stadium chant that alternates directions, but it's not a general cheer.
A key tradeoff: 'Hup' can sound old-fashioned to younger crowds, but it's universally understood and respected. 'Kom op' is more casual and modern, but less iconic. If you want to blend in, listen to what others around you are saying and follow their lead. You can also learn a few short chants like 'Oranje boven' (orange above all) or 'Wij zijn de beste' (we are the best) for bigger moments.
For next steps, practice saying 'Hup Holland Hup' with a strong, short 'u' sound (like 'hup' in English 'up' but with a slight push). Watch a Dutch match on TV or in a pub to hear the natural rhythm. Avoid overusing English cheers like 'Let's go' or 'Come on' if you want to sound local. Most Dutch fans will appreciate your effort, even if your pronunciation isn't perfect.
Honestly, the best way to learn is to attend a match or join a local fan club. You'll pick up the nuances quickly. Remember, cheering is about energy and participation, not perfection. So just shout with confidence, and you'll fit right in.