Hi Sam!

Looks like a fun project! As previously suggested, I'd try to create as much airflow as possible to stunt the duckweed and algae growth. Then line up the wheelbarrows and get rid of the stuff by large nets and buckets. A nice sturdy boat will give you an advantage giving it a total clean-up. When the surface is cleared out I suggest putting in an aerator in to improve the water quality and restore oxygen in the deeper depths. Duckweed hates a well-oxygenated/moving water.

Before you stock, see what you got first. I'm sure you got something swimming around in there. Buy some Trout Magnets (salmon color is my personal favorite). I call it my "inventory lure". It catches anything and everything, fast. Fish think it's a little worm that fell in the water and attack it instantly without any presentation.

Do you know if you have anything swimming around in the creek? Might be a great, cheap way of adding feeder fish to the predators. Throw in a minnow trap with dog food and bread and leave it overnight and see what you got. Always identify the fish before tossing them in your pond. Keep a log to keep the numbers controlled in the beginning.

Once you get the water and surroundings in good condition, I'd stock maybe two dozen LMB, about 6". The pond looks quite small. It may handle more after aeration but if it has water level issues during dry months then I'd stock a little less to be safe. After time they'll spawn and nature will take it's course in numbers.

I have a small pond myself. This is what I did (I too have a small creek broadside to our property) and have a healthy pond.

Fishing is my stress relief.