First off get the supplies you need, depending on your ranged level and what ranged armour you can wear just wear the approriate one for maximum ranged bonus although this is not required. It usually consists of an amulet of power, green d'hide and/or hard leather body, short bow, coif, arrows. This is a guide to some what give you an idea of training places, what levels you should expect. Where the general locations are. It is NOT a in depth highly detailed guide!!
Ranged levels: 1-15
Range chickens by champions guild or lumbridge, now if you've played long enough im sure theres ONE place you know where chickens are just simply stand behind a fence and start ranging, that or range the chickens and pick up the feathers for money or for fishing.

Ranged levels: 15-30
Range cows, at Lumbridge simply kill them pick up your arrows and collect the cow hides for money
Ranged levels: 30-40
Go to the monastery where the prayer guild and monks are located, there are safespots if you do happen to get attacked you can simply walk over to one of the monks and ask them to heal you.

Ranged levels: 40-50
Train at flesh crawlers there is a safespot somewhere there, i suggest going to a full world and walking down there you will most likely see other players training there and find the safe spot.
Ranged levels: 50-60
You can stay at flesh crawlers or I suggest hill giants, there are safe spots and easy to kill
Ranged levels: 60-70
Ice Gaints go to the end of the cave hide behind rocks and range em
The enterance can be found

Or you can train it at Karamja at lesser demons, but its usually packed and hard to get a kill.
Ranged levels: 70+
From here on out its the best way to train ranged, the last floor of the secruity stronghold where the Ankous are. There is a safespot pic below

This is a guide to some what give you an idea of training places, what levels you should expect. Where the general locations are. It is NOT a in depth highly detailed guide!!