The Floris mod allows for several ways to start the game with your new character. Although these paths are all unique, they boil down to the same goals: Setting up some form of steady income, companion hunting and getting gear for your character and companions.
In case you decided not to use the "Gather companions" options, the very first step of most new characters will be to go from city to city to gather some base of companions. Usually it is preferable to do this without an army, since this makes it easier to dodge the bandit parties lingering between the cities. Be careful around Khergit and Sarranid cities, since the mounted bandits patrolling these lands move particulary fast on the overland map.
Though being enlisted can be very rewarding, it can also make your mid game very frustrating if not done properly. Playing as a mercenary for a lord is done by talking to your lord of choice and choosing the "I would like to enlist for your army" option. The best strategy is to enlist with a lord who is garrisoned in a city where you will be spending a lot of your mid game time. While in service, you will be able to enter the town where your lord's army is stationed, so you will be able to buy new land or collect your due without having to ask for leave. The main thing as an enlisted freelancer is to plan your progression using the ingame troop trees listed under "Reports". This will avoid having to ask your lord for a re-positioning which will set you back one or several tiers and thus require you to gain more experience to get to the top tiers. Be wary as an enlisted soldier, time progresses very fast, and the world and factions tend to change. Also, while enlisted you can't gather your own army, but you do get a lot of experience and level up quite a bit, causing the bandit parties to grow bigger. Be sure to create some base of steady income, so that when you decide to venture off on your own you will have the resources to gather a big army.
Another way to spend your early game is to go from town to town hunting for tournaments. If your fighting skills are up to par this can be a very profitable way to spend your time. The problem here is that fighting in tournaments doesn't net you loot, forcing you to buy all your equipment, which is very expensive. Also, as always, be sure to invest some of your money so that you will have a steady income later in the game.
If you have some points in prisoner management, another way to spend your early game is manhunting. This strategy revolves around using blunt weapons to knock out as many enemies as you can, and sell them to a ransom broker in towns. The pros of this strategy are that you will recieve loot from the fights for your companions and yoursef, and that you will have the chance to start gathering an army very early in the game. Also, it is commendable to recruit manhunters into your party if the bandits have capured some of them. They increase your prisoner slots and are standard equipped with blunt weapons. If you decide to use this strategy it is worth choosing the "Slave-hunter" option in character creation, since it gives you 3 point in prisoner management without having to spend too many points on charisma in early game.
Although quests are often overlooked in sandbox style games, they can be very profitable. Be sure to pick up quests in the villages and towns where you will be spending midgame time, since higher relation with villages will increase the amount of villagers that volunteer to fight in your army.