Having experienced quite a few different eJ bases so far I would say take LGW to start. Mini bases are great for lifestyle once you’re older and sorted with command etc, but initially you will get very bored doing the same route over and over, and over again. To develop you need exposure to different destinations, different captains with “differing” outlooks.
Having seen what I’ve seen now, I’d start at LGW and then if you fancy some sun and nice food get yourself on the MXP list as soon as you can. At least you retain the route network and actually make some money to pay off the loan!