Mozambique is definitely not the best destination for a first trip to Africa at all. You will have a rough way to Africa. You will have to learn a lot.
To have to bribe police or military police is common in most countries worldwide. You will get to know about it and realize it when you will do more travelling worldwide.
Put a USD 10,-- note into your passport when you get controlled by police or military police. The USD 10,-- note will go or will not go.
Then it's up to them. And nobody can ever accuse you of trying to bribe them.
Enjoy and happy travelling. And good luck. You will need it.
I don't envy you for going to Mozambique.
Countries like Morocco, Tanzania, Botswana and Zambia are much better.
Live long and prosper.