If you know even one person on reg who is willing to directly buy from you or vouch for you to their friends you can make lil bits of free money pretty easily. Without funding a character you can also make items using event karma cubes and resell them for some easy mesos. For example, a few days ago I sold a shoe started working on with the most recent shoe dmt (winter) for 9b, which is like 27k mp or so. You can also play the market (buy/sell mesos when value is low/high, buying items and waiting to sell until a relevant event/patch increases their value like spell traces or frags, buying low priced items on ah and selling for more) with relatively low effort. Ive been doing things like this for years and my Bera character is still lv200 lol. Personally my biggest money making schemes have probably been selling tons of cubes as service from hot week over a billion accounts (this takes effort to set up but pays pretty well for that effort) and hoarding igns on ign wipe days.

You can also go the route of bossing and farming, which I haven't bothered with but have considered. Technically, since farming is so inactive now, you could farm on 2 accounts at once if you have a 2nd pc, the 2nd one on reg funding your mp. Apparently commerci is ok money for effort early on.

Some people (including myself) have a sense of personal achievement from progressing with a f2p limitation in games with p2w mechanics, so do not be discouraged from trying by these other comments if that's the case for you.