How to make smooth coconut ice cream without machine, not icy, not too hard when storing

There are some difficulties when we do homemade ice cream, such as:
- Ice cream is not smooth, but icy
- Ice cream is too hard when storing
- Do not have enough equipment at home
Do not worry, just using a blender, we can easily make a fantastic ice cream
Ingredients:
- Thick coconut milk: 600ml
- Vanilla powder: 2,5mg ~ 1 tsp
- Whipping cream: 300ml
- Sweetened condensed milk : 150ml
- Corn starch: 2tbsp
- Salt: 1/5 tsp