Im a computer eng. student in last semester and I have to submit my graduaition project I am making indoor navigation with flutter and ble beacons now, my problem is I can find beacons and finding my location as well but I cant draw routes and loading maps (building map) too can you help me about this? thank you so much :)

I can put my beacons on drawed map with lines so it is a basic map and I got building's map but I dont have any idea how or where should I start
I can walk on map without lines and if I go a to b my animation moves slowly a to b but not real time also
I tried load all of drawings/plans of building but it was so heavy. My app dont respond anything when I open navigation
I need to simplify it
So my problems that need to solve

Drawing routes to a -> b
loading the map with lighter version