Personal experience here:
I had a 2.9-3 GPA (don't even remember), but coming from a Greek engineering university, I actually had a 5-y diploma which equates to a master's degree, so that helped me (and lots of other Greeks) as we were effectively coming in for a second post-grad. I also had a lot of extra-curricular academic projects that I believe helped my case. I didn't even expect to get accepted to be honest.
For a bachelor's at 2.4 GPA (60%) it's going to be quite tough. Only scholarships I know of were through exceptional academic performance in previous studies and with criteria to continue to do so during time in ETH. I think it's best if you talk to admissions directly and see what they have to tell you.
Regarding finances, it is not going to be easy. I came here with almost nothing (a lot less than 10k), and even with an EU passport I needed a letter from my family that they will support me financially, which they couldn't, but nobody requested to see their financials. Rent was too expensive (800 CHF) because I didn't expect to get in, and I didn't have time to apply for a dorm when I realised I'm coming to Switzerland.
I scraped through for about 6mo, got a very small loan of a couple k from family I had in Switzerland, and managed to get a research assistant job at uni with a steady salary (not a teaching assistant). It wasn't much at around 1500 CHF/mo, but I paid rent and groceries and it got me through for about a year, when I got my first internship. After that I was on my way to paying back family and getting my life in order.
To this day, I never stopped working for a day after getting that first position at ETH, and having to work full time, commute, and do an MSc in ETH was not easy. Everybody that had the finances to study without distractions were finishing in 2years and it took me the full 4. I was writing my thesis while starting a new job in a new industry which was also quite tricky.
A lot of potatoes, a lot of cheap frozen pizza, a lot of freaking rice. Juggling overdrawing limits at my bank with bill due dates, and calculating how many reminders can I get on bills to make the cash flow work.
In the end, it was well worth the effort. Besides what the syllabus had to offer me, some of the people I met are quite a network and have helped tremendously in my career.
I think staying in Greece or going back soon after I came to Switzerland with an offer I received would be better at that point in time financially. I stuck with it, played the long game and it worked out in my favour.
But I was not sleeping many nights and I was also quite lucky to get that first position in ETH. Do not take for granted that you will find a job. With a non-EU passport things will also not be easy unless you get lucky with a professor. Even if you do, a teaching assistant position will not get you enough to cover all of your expenses. Please also keep in mind, that with a non-EU passport it is going to be very difficult to get a job here as a graduate as well, which also dilutes a bit the usefulness of a local degree. Thankfully ETH is an amazing and reputable place, so it opens doors globally in engineering, but maybe it's worth exploring other options in other countries that might have scholarship programmes that are relevant to your situation.
I wish you the best of luck, you're going to need it