I was just wondering what the best strategy is, or at least what some people think is the best strategy.

on what server? rep casher/farmer all-x are easy and demo farmer all-x too, commy indy isn't bad either but then you need to sell at least 2 times per day.

A strategy that is relatively easy for a newcomer and that is still very effective is either rep-casher or demo-farmer.

The basic idea of each:

Republic government gives the player a Per Capita Income bonus. You build virtually nothing but Enterprise Zones (which also raise Per Capita Income) and Residences (which increases population). You basically get a bunch of money from tax dollars and use that money to buy food, military, technology, etc. You'd focus primarily on business and residential techs.

Farmers build virtually nothing but farms and sell food to get the cash to buy military and technology. You'd focus primarily on agricultural tech (although it'd be recommended to get bus/res as well, just like the casher). Democracy is probably the best government because you can push your technologies even higher and you don't have to pay market commissions for selling on the market. Fascism is another good choice because you do get a food bonus on fascism.

There are plenty of other strategies, but since you're relatively new, I'd recommend one of these two. It's very possible for someone who is more of an expert player to pull a top 100 or top 10 finish with these strategies, so they won't handicap you due to just being a "newbie" strategy.

What is the advantage of the farmer? vs republic?

Well, it's not necessarily Republic vs. Farmer.
It's really Casher vs. Farmer.

Neither is necessarily better, but based on how market conditions go in a set, one will end up being better.

As stated in the previous post, Casher is a strategy based on getting as many people as possible and raising their Per Capita Income (PCI) as high as possible so you can bring in large amounts of tax dollars. With those tax dollars, you buy all the other goods/tech you need. Republic is often the best/easiest government type for Casher because Republic offers a PCI bonus for your citizen. Some people might argue Democracy is better, but you have to get your tech levels incredibly high to really take advantage of Democracy bonuses, so for a beginner player, Republic is a far better choice.

Farmer is a strategy based around building virtually nothing but farms and then selling your excess food in order to buy the other things you need (military/tech/oil). The reason I would recommend Democracy or Fascism is because Fascism gets a food and oil production bonus and Democracy pays 0% commissions and has a higher maximum technology level, so between not losing 6% on each bushel and being able to top out your tech levels and produce more than most other governments, you'll do best with those.

cheap tech and cheap bushels = casher better

cheap tech and bit expensive bushels = bit 60/40 to farmer

expensive tech and exzpensive bushels = farmer better

casher needs 2-4 techs and farmer 1-5.