You will have to describe the problem while asking somebody for help.
Use There is … to say what the problem is.
There is a cat under the bed.
There is a problem with my laptop.
There is a smell of gas in the kitchen.
There are mice in the storeroom.
If you don’t have what you need, use There isn’t…
There isn’t any milk in the fridge.
There aren’t any clean bed sheets.
There isn’t enough food for everyone.
There isn’t anything to eat.
For some problems, you can use I’ve got…
I’ve got a problem.
I’ve got too much luggage.
I’ve got too much work.
If you don’t have what you need, use I haven’t got…
I haven’t got his phone number.
I haven’t got enough money.
I haven’t got his address.
I haven’t got anything to wear.
I haven’t got anything to drink.
I haven’t got anything to read.
If your problem is that you can’t do something use I can’t…
I can’t ride a bicycle.
I can’t walk without support.
I can’t see properly.
I can’t open the door.
I can’t find my phone.
If you do not understand something, say I don’t understand ….
I don’t understand French.
I don’t understand what he wants.
I don’t understand how to operate this machine.
Saying what happened
To say what happened, use I have…
I have forgotten my passport.
I have lost my keys.
I have broken my arm.