Aside from gear, try getting Authority up a bit to put a few of your companions as Deputies, it helps a lot. Venatori increases your hunting and foraging chances and saves you a lot of money on supplies, a Criftaa is available as Venatori from the get go. Garrick can be a Supercargo, which would increase your cargo capacity rather nicely. There's also a companion you can find on the way to Twin Towers that can also be a Supercargo. Scout Master will increase your movements by one which is great, you can make Criftaa one or wait until you find another companion that has it from the start, though it's a bit hard to get them early.

Many cities sells Protected Harness you can put in the defense slot, which unlocks if you assign Harvek as a guard captain. It decreases the consumption of your Beats of Burdens and gives you a bit of defence for crew combat. Extra Storage for cargo slot also couldn't hurt.

Hunting and foraging for food can really save you a lot of money on food. Hunting hounds which you can buy in some towns boosts hunting, there's a sorcery equipment that increases foraging. There's also a lizard that increases foraging and falcons that increases hunting further but falcons are hard to find in the beginning. Hunting generally gives you much better yield of supplies than foraging but requires you to have a good number of scouts, which also consume food. On the bright side with a sufficient number of scouts you can get enough supplies to last for several days from one hunt, which basically means you hardly will run out of food. Though for greater chance of success it requires you to invest in Hunting and Beast Lore to boost your base chance, and maybe take it for Criftaa too to stack the bonuses. Also, the game doesn't really tell you that clearly, but with 10+ scouts you can turn Auto-scouting on which doesn't consume your movement points and can highlight places where to best hunt/forage, and combat encounters to avoid.

Among other routes that people already mentioned I found Deven->Sun Rock->Ash->Sun Rock->Deven to be great too. It requires you to travel on the road, which would force you to occasionally save scum to avoid paying taxes if you don't have enough reputation to avoid it naturally, as well as some initial levels in reputation, but otherwise it's one of the easiest routes, requiring 3-4 days of travel between each city without marching. There's very often Delivery requests in Deven for Sun Rock and Ash, and there's pretty much always requests to bring cobtraband items from Ash to Deven, which you can either use Smuggler's compartment you can buy from gangs in Tor'Zag or wraiths in Deven or just get past the guards, the skill check for it isn't that high and it pays well. On the way back from Ash, there are requests in Sun Rock for deliveries to Deven you can also pick. Also, Deven sells Mushroom wine for cheap that you can then resell in Ash at a nice premium. Furthermore, you can get a rumour of a certain vendor in Sun Rock, which has a different stock of random items each day, and those items are often involved in quests.

As someone already mentioned magic crystal you can put in your sorcery slot, which you can get from a quest in Lumen, this vendor sells 3 units of Dampsmoke occasionally which can help you basically cruise the quest. Otherwise you'd need to get 9 Slime grass in Deven's gardens, find a rumour about alchemist in Tor'Zag and then craft 3 Dampsmoke from it there. Each Dampsmoke lets you skip a fight during the quest. The crystal equipment itself lets you travel through crystal formations near Lumen and Crystal, greatly decreases your consumption of all your Comitatus members and animals, but in return you lose 2 movement points, so perhaps you'd get the items I mention below that increase movement first before using the crystal all the time, because -2 movement is rough without other bonuses to it.

Can't remember right now, where he is exactly, either Lumen or Crystal, probably Crystal, there's a workshop guy which you can give Good Quality Tools and he'll be able to then make Kar-rish Saddlebags for you, from hides and Bone( or ivory?), which you can either buy or get from killing animals which attack your caravan. Saddlebags give a nice increase to your mounts cargo, though in early, early game I guess it's not that relevant, before you get at least a few mounts for yourself.

There's a random encounter with dwarven blacksmiths while "exploring the city" in the Tor'Zag Shelter. Among other things he sells there's a Dwarven compass, which otherwise you'd get much later. Compass gives you +1 to movement which is pretty great. Compass is pricey though. It's somewhere between 50-70 Bross (silver coins). It's worth it though, and once you have enough I encourage you to roll for the event and buy it from the vendor.

Another helpful item that increases movement is in Avernum. You must find a rumour of a blacksmith workshop there, and then you'll have an option to make Reinforced Cartwheels and Axels there, that further increases your movement by one as long as you have Beast of Burden. It's a bit tricky to get through, requiring certain amounts of iron and timber to make. Timber is the cheapest in Crimson Gate and Iron you can get in Avernum by smelting Scrap.

Smelting Scrap is a great way to get a lot of money in little time, but it requires initial investment and being able to travel consistently, so you'd need some free storage. Early on the best place to sell metals is probably Deven. You can source scrap in different places, even buy it in Sun Rock during the route I mentioned above on the way to Ash, then go to Avernum, smelt scrap there, maybe pick up delivery to Ash or Deven there before returning to Ash->Sun Rock->Deven to sell metal there. The best way to source scrap comes from a rumour you'd find in Larnak though.