How Can i Speed up the tiles loading in the map

Hi from last couple weeks, i am learning OSM , i have setup own tiles , they all good. I am using rendering

Ref : https://wiki.openstreetmap.org/wiki/User:SomeoneElse/Ubuntu_1804_tileserver_load#An_example_site

 render_list -n 1 -s /var/run/renderd/renderd.sock -z 0 -Z 20 -m ajt  -a

now I have couple of question . Initially our services will be only for particular country , later on we will exend that to few other countries. we will provide TRacking solution for a particular country only and we are expecting lot of vechiles so the reqeust will be very high.

I wanted to know how can I speed up the loading of maps ( one country ) ? basically i am trying to understand if i can avoid postgress with every times user try to load a map.

if i Render all tiles betwen 0 to 25 for a country before hand, will it make the map loading faster ? if Render before hand by using "--z 0 -Z 20 " will it still require to use postgres when servering map ?

(we will use the map in Dekstop and Mobile for tracking solution.)

I have lot of space to hold tiles ( so no worris about that) , just trying to see how can i avoid on demand rendering with postgress also if i can serve tiles from a static place i.e web server.

Additional Note, if i Look at this one

https://wiki.openstreetmap.org/wiki/Creating_your_own_tiles

section "Creating tiles using Mapnik and generate_tiles.py"

When everything works, use generate_tiles.py to create 1000s of tiles in a special hierarchy of folders
Copy/move tiles into your webserver's document root.

does it mean, i will not require postgress or further rendering at all ? if yes it should be fast to load right ?

Please let me know.

Thanks for the help.