Should you finish one story before starting to work on a new one?

You can or start a new one before you finish the first one. Both ways work. It depends on your enjoyment level. Do what you want to do.

I do the same thing as @Sarah. I've got four or five on the go at any given time. There's nothing wrong with working on more than one story at once. Sometimes it's hard to stay focused on just one thing and it's better to jump into something that you're excited about that will keep you writing than it would be to stay stuck at the same point of a story agonizing about it. Also, sometimes the best thing you can do for your story is distance yourself from it for a few months, it will help you get perspective and reinvigorate your passion for it. Just make notes of plot points that you have in your mind before starting something new. Sometimes when I go back to something after a break I read it and think 'I know I was going somewhere with that, but where?'. And you should always be writing, even if it's just a side project or exercises.

As a writer myself, I often switch from novel to novel and from poem to poem. If I ever feel like I'll lose track on my previous work, and I have extremely good ideas for a new novel, I just make an outline for the new one so I won't forget it and continue on to finish the first one. I also have ADHD so I can never really finish anything! But then again, I think a lot of people get great ideas and get so excited they want to start writing the greatest novel in American History as quick as they can...and I think that's good and fun. If you feel you can switch between the two, I say go for it! Let your creative juices flow and just have fun with it. Remember, though, not to mix up the plots. That happens sometimes. But to me, it sounds like you've been writing for quite some time and can make accommodations as needed. I wish you luck with your endeavors and keep writing, mate!

Well obviously songwriting and writing a novel are two different things but when I'm writing and have a new idea I always jot something down. Its good, sometimes thinking of new material sparks new ideas for your current song, or in your case your book. I would though apply most of your time to your current book so you don't change your style of writing unintentionally or write another story with the same style of speak. If you are mentally able to switch between the two then go ahead, but be cautious.

If you want a surefire way to go nutzoid, sure! Start the 2nd story xD Kidding. It's up to you. Sometimes it's a good idea just to get the ideas out on paper so you don't forget them but I'd recommend sticking to the story you have more ideas for.

Of course it's alright! Many well-known authors say that when working on a long-term project, it helps to continue feeling inspired by working on other projects in the mean time.

It's really up to the writer.

Some like to work on 5 stories at the same time and others like to work on one.

Since you said you have been getting ideas for another story, i suggest you try working on more than one story at the same time and see how that works out for you.

Good luck <3

Not if it's going to take longer than two years for the new one also. I would keep one project as your main one and the other spare time, unless you're like me and can finish a first draft in less than three months, revise in less than another three.

It really depends on what you can handle...for me, I have like, seven stories and I jump back and forth between them when I get stuck on one... You can try it out, and if you don't feel like it's a good idea, just wait :)

i do that all the time and i forget about some then come back to them and have great new ideas i'm working on about 10 right now