It depends for each person. I'd say if you can make yourself solve at least 1 problem every day you're well on your way to improving.

Anything is possible of course, but you should set your goals based on how you're doing and what you think is reasonably achievable in the near future. Once you're able to have gm-level performance on one or two contests then I'd say it's time to start thinking about when you can reach red.

There are many resources on how to start practicing, which is why repetitive blogs like this get downvoted — just do a quick search and you'll find everything you need. If you're ever in doubt over what you should do, just keep solving problems.

It's not the quantity but the quality...or so my girlfriend told me.

Red coder — no Blue or purple — more yes than no