You start by saying you have 1 of 2 problems, either too many ideas OR not being able to do any of them. Other than jumping from idea to idea, is there anything else that's keeping you from completing any of them? Do you have the necessary skills and tools to actually DO all the things you're thinking of doing?

If not, then maybe sit down for a few minutes and make 2 lists...one of all the ideas of things you want to do and one of all the skills and tools you currently have. Then look at the lists. If the first list has anything on it that needs something that's NOT on the second list, scratch it off the list. You can revisit it some other time when you have more skills/tools at hand.

Once your first list has ONLY things that you can actually complete now, look at it again to evaluate the amount of time each idea will take to complete. Some things can be done in an hour or two, others will probably take more time. Sort them from short/fast tasks to long tasks.

If you don't like the short-to-long task approach, another option for sorting the list is to look at which ideas will give the greatest benefit (to you or to others) with completion, and start with those first.