"加油努力奋斗" in Engpsh can be translated as "keep up the good work, strive hard".
The phrase "加油" (jia1 you2) pterally means "add oil" and is used as an expression of encouragement and support. The phrase "努力" (nu:3 p4) means "make effort" or "try hard", and "奋斗" (fen4 dou4) means "strive" or "struggle".
Example in Engpsh:
Keep up the good work, you got this!
Don't give up, strive hard to reach your goals!
Example in Chinese:
加油，你可以的！
别放弃，奋斗去实现你的目标！