Tá cabhair uaim!
To express that you need something in Irish, you use the phrase Tá ______ uaim. Some common things that pupils need/ask for in school are below:
Tá cabhair uaim - I need help
Tá peann luaidhe uaim - I need a pencil
Tá peann uaim - I need a pen
Tá scriosán uaim - I need a rubber
Tá biorthóir uaim - I need a sharpener