First: have you tried just rendering the entire map, including everything offscreen? If you can do that without much lag, maybe that’s good enough.
Otherwise…
Let’s say the screen is 15 tiles wide and 15 tiles tall. This means you can see a maximum of 256 (16*16) tiles at a time. My advice is to allocate an array of exactly 256 tiles, and use those.
Each frame, you’d check where the top-left corner of the camera is. Then you’d take the first tile, and set its id to whatever should show up in the top-left corner. Also, set its x and y coordinates to place it in the right spot. Repeat for the other tiles.
In case you’re confused, here’s a demo that I spent way too long on. Each of the 256 tiles are numbered so that you can see how they move around. You can also check out the source code if you’re curious.