This answer is for American English: 1. I endeavor to achieve my goals. 2. I should endeavor to earn money. (To "earn" money is a better way to say it than to "get" money.) 3. The noun "endeavor" doesn't work in this context. If you are trying to use "endeavor" as a noun, a better way to say what I think you mean is this: Through persistent endeavor I should (or I hope to) achieve my goals.

Oops, I meant to post my response here. *Is it right? Not really. Below are the grammatically correct versions of your sentences (although they still sound awkward to be honest). I endeavor TO achieve my goals. I should endeavor TO EARN/MAKE MORE money. Completely wrong- "I need much endeavor for achieve (or achieving?) my goals" (you would also never say "for achieve", "for read", "for talk"... although under under certain circumstances you could say "for achieving", "for reading", "for talking") It should say "I need to try hard to achieve my goals". I should point out though that "endeavor" is rarely used as a verb. It's used much more often as a noun. For example "his endeavor to climb Mount Everest failed miserably". To be honest though, it's a word that if used incorrectly sounds really awkward since it isn't used too much (though it is used) to begin with. Endeavor is essentially a synonym for "attempt" when it's a difficult task.

*Is it right? Not really. Below are the grammatically correct versions of your sentences (although they still sound awkward to be honest). I endeavor TO achieve my goals. I should endeavor TO EARN/MAKE MORE money. Completely wrong- "I need much endeavor for achieve (or achieving?) my goals" (you would also never say "for achieve" although under under certain circumstances you could say "for achieving") It should say "I need to try hard to achieve my goals" I should point out though that "endeavor" is rarely used as a verb. It's used much more often as a noun. For example "his endeavor to climb Mount Everest failed miserably". To be honest though, it's a word that if used incorrectly sounds really awkward since it isn't used too much (though it is used) to begin with. Endeavor is essentially a synonym for "attempt" when it's a difficult task.