What kind of fuel are you using? If coal make a deep burning bed
right up to the bottom of the fire hole.

The way I start is with some charcoal briquettes broken up to fit
through the "hole" and soaked in lighter fluid. Of course my
artificial draft from my shop air is in the stack to make air pass
through the fire.

When that is burning well start adding coal and as soon as the
pressure gauge is off the pin remove the artifical draft and use the
blower. When the coal is burning well, keep adding a bit at a time
till the fire is up to the firing hole.

When firing a locomotive the pass word is small and often. Don't
overload the fire box with fuel, add a little at a time and make sure
the last shovel full is burning, then add a little more.

Then what kind of coal are you using? Some coals are better than
others to fire a small locomotive.

When the safety lifts then you can start oiling your wheels, valve
gear etc, make sure the lubricator is full etc. By that time you
should be ready to go out onto the main line. Remember to keep a deep
bed burning hot and add little and often.