My bike starts sometimes, and other times it doesn’t? ?

Since you provide NO DIAGNOSTIC INFORMATION, it's solar flares doing an electromagnetic pulse thingy on your ignition thingy. Glad to help.

wont start? Does she  always Crank? Check kill switch, is clutch handle In, in Neutral, side stand Down? Some have THREE "safety" switches.  If she cranks but sometimes slow, it Might be 10 degrees out there . IDK, I have no idea where you live or age of battery. If slow, bite bullet; get new one. Extreme cold/heat and vibration severely shorten a battery's life.

For all We know, it might be you have No right leg...or, Left  leg if Italian bike. 

M/M/Y? is the gas On? is it Flowing? pull the line At the carb(s) and see?
If a newer feulie, do you Hear F. pump when ignition on? A whine,  then stops? Your fuel gauge can be faulty. Try a shot of starting fluid. If a Pop, fuel problem. no Pop, spark or jumped timing.  Possibly bad vacuum leak--are all vac lines On?  Try  fresh gas. 
 Or as adam  suggested, bad fob if you have one. Check its battery...

Also, check for good spark At a plug.  Check fuses, a loose one or bad connection at fuse box can cause intermittent ignition/ fuel pump

Use the choke on a cold engine. Turn off the choke when the engine is warm.

That happens.......

Does it not crank when it does not start?  Or does the bike cranks but will not start? Two entirely different scenarios and two different diagnostic procedures.  Replace the battery and see if that fixes your problem for now.

We all get that way sometimes

make and model? Does it have a key fob?  Need more info. 

My "bike" starts every time.  All I have to do is PEDAL IT!  Welcome to the CYCLING section of Yahoo Answers - as in BICYCLES.  

I would imagine your "bike" is actually a motorcycle.  Try relocating the question to the appropriate section.  All Categories > Cars & Transportation > Motorcycles  https://answers.yahoo.com/dir/index?sid=396546040

My Triumphs ran rich. Sometimes needed  throttle cracked  to start   with One kick when warm,.

I think you have a problem starting at all. Maybe check choke/ticklers/mixture, maybe plug is too cold.

You should specify your issue.

If it doesn't start it means you aren't pedaling it.  You posted in the Cycling section where questions are answered about bicycles.   You relied on YA to post the question for you instead of doing it yourself.   Use the edit icon to move your question to the Cars & Transportation>>Motorcycle section.

That's tough luck but unless you provide more information such as make and model and symptoms that caused intermittent starting no one can help you here. We can only guess what's wrong. 

Is it colder when it refuses to start? The way a battery works is chemical and that process is affected by temperature. OTOH some bikes (big singles seem particularly affected) once warmed up and ridden will refuse to start up again while the engine is still warm.

So you have to do some detective work. Start* by removing the spark plug(s) and examining it, is the gap correct, is there a residue, is the electrode degraded?

Then get yourself a multimeter and check that your battery is holding charge and is being charged.

Try to find out the cause of the problem before splashing money out.

*because this costs nothing and is relatively simple to diagnose.