Is it me or is there a HUUUGE difference in beginners world vs Modern Times?
Almost seems impossible to make money..... Tried everything, but no difference.
Seems VERY odd since payment (Credits) has been done. Am I the only one with this experience?
Modern times worlds have fairly high fuel prices in comparison to other game worlds, especially during the second half of the game. Since we happen to be in the second of of the game, you're going to be dealing with paying 2-4x more in fuel costs for everything compared to the BW scenarios. Additionally, since it is an established game world, airlines have had time to settle in, buy planes and fill out a lot of the demand in the game world, thus, as a new entrant, it becomes a bit more difficult to pick a base that does not have a dominating airline.
Thus, taking a quick look at your MT airline in SFO, you have a single A310-300. At the current fuel prices, those are rather difficult to make money on because they burn a lot of fuel in comparison to the number of passengers that you carry. Additionally, the way fixed costs work in the game, is that for the most part, a single plane airline will struggle significantly to "make rent", thus, getting profitable with a less expensive to acquire fleet type but flying several planes can be a better way to start. The other thing to keep in mind is that your loads (and profits) will be very low until RI begins to climb - this can take over 6 game months to reach 100 (you should be making OK money at least 2-3 months in on a new route).
Overall - it might help to request a mentor to help get you started, but for sure, starting midgame in MT is one of the most challenging things you can do...