It truly does depend on what difficulty you are playing on (wide warmonger is nearly impossible on DEITY) and what map size (smaller the easier)
Im gonna assume that you are playing on the biggest map(if you are not this guide would still help you and it would be EASIER because the map is not as big) I am also going to assume that you are playing Immortal difficulty(Never beat deity with Wide empire
).
1. if you want to go Liberty, As soon as you start off go scout -> then monument. And for the Policy order go Liberty opener->republic->collective rule->citizenship->meritocracy.
2. Make sure in your citizen management ALWAYS set it on production focus for all cities. I know that food is important early game. But the reason why production focus helps is that you should still manually select and lock the growth tiles but still do production focus. WHY? Because if you are 1 turn away from growing, and you end your turn. if your city has 3 pop, and you have food focus therefore next turn your 4th citizen will work growth tile. But the food will not carry over from the 4th citizen. you will still merely have the excess food from the 3 citizens only. But for production it does carry over! if your cities are all working food and you have 2 production, your scout only needs 4 production to finish, you are about to grow next turn and your highest production tile is 2 production, you end your turn, you will get your original 2 production AND the 2 production from your 4th citizen. Therefore you have finished your scout in 1 turn instead of 2! Then you can switch your 4th citizen to a food tile. This strategy is very important to gain an early advantage and is vital for liberty empires.
3. Settle your cities where there is at least 1 unique luxury and if possible, a unique luxury AND near a resource that lets you build circus. Remember that with wide empires you do not grow indefinitely because happiness is an issue. You should not grow pass your local happiness! Your cities should grow to around 8-10 pop(2 happiness from Colosseum, 4 from lux, 2 from zoo, and maybe 2 more if you have pagodas and you will never get stadiums since those are too late on the tech tree). After you reached that growth cap you should go to citizen management and tick "avoid growth" and then you should switch as much of your citizens as you can to production tiles and if possible tiles with production and gold like copper as wide empires have a gold disadvantage as they have more building and unit upkeep. But remember to never work gold only tiles. Also when i mean "as much of your citizens as you can" I mean that you should keep some on food to at least keep you on starving, it doesn't matter if it takes 1000 turns to grow as your cities are now production focused.
4.Wide empires have a gold disadvantage (more buildings means more upkeep) Culture disadvantage(no legalism and the more cities you have the more your policy costs go up) a science disadvantage (again, the more cities the more expensive techs are) and a growth and happiness disadvantage(mentioned above). But they have a production advantage so they can train more units. But tall empires will tech past wide empires if the wide empire does not take cities (this will usually happen during late industrial or early modern era) and therefore will have stronger units and Quality>Quantity in civ 5.
5. If you are not playing random Civilization then I recommend you pick these civs:
Huns- Battering rams can solo cities and city states. Basically free city if you manage to upgrade your warrior with an ancient ruin. And +1 production on pastures and free animal husbandry will help early game rush and snowballing. Horse archers are the strongest unit in the game during ancient and classical era.
Arabia- Camel archers OP and kill everything during Medieval and Renaissance, also the double quantity on Oil will help you mass battleships and Air units during modern and atomic.
China-Paper factory makes libraries give gold relieving you of both science disadvantage and gold upkeep. Chu ko nu's are very powerful during medieval.
Egypt- War Chariots are extremely powerful unit costing no horses. Burial tombs give you happiness and faith and requires no upkeep like the temple, this makes all your cities 2 pops bigger!
Mongolia->Maybe... city states are crap anyways but can prevent diplo victory and khans are very good as you will go to war a lot. Though keshiks are an OK unit. Not as good as the camel archer but since the Ai are stupid and this is turn based then you can deal a lot of damage through focus firing as they can move after attacking.
You also play as shoshone I think? They may be "The Great Expanse" but in reality they are good for tall empires and not wide.
I will write more later. I just have to take a break now.