Chainsaw Repair

It's probably just your starting technique.  The instructions on that decal are a bit lacking...

Yes you have to set the throttle lock.  Squeeze the trigger, pull the little black nib sticking out of the top/front of the rear grip rearward, then release the trigger.  The throttle latch should then stay set until you pull the trigger again.  Be aware that when the engine starts with the throttle lock engaged that the chain will start moving.

Pull the choke and the pull the rope repeatedly until you get the first 'pop' from the engine.  Do NOT pull again after that 'pop' with the choke all the way out or you will flood it.

Push the choke in 1/2 way and then pull the rope repeatedly until it starts.  Ease in the choke the rest of the way, release the throttle lock with a pull of the trigger, and keep the engine running with slight 'blips' of the throttle until it warms up.

Being left handed shouldn't matter.  I'm left handed and I'd start that saw by holding the handlebar down with my left hand while pulling the rope with my right (with the toe of my right boot on the 'boot plate' at the bottom rear of the saw.

When the saw is hot.  Don't use the choke.  It should restart without the throttle lock......but may require the lock to be set.  The saw is also likely to not be tuned correctly.  That'll make things difficult too....

In warm weather you can often skip the 1/2 choke step during your initial cold start.  Instead, after that first 'pop' at full choke, push the choke fully forward before pulling the rope again.