I've ran my first marathon last year and looking ...

My advice, pick the first one, train for it and have it done. Afterwards, Call for the decision on the second one. Consider how fatigue your body is, what's your mental state, and how are you to deal with another vigorous training routine. Good luck

I would seriously think on going for the longer, or more wanted one, only. You will have a hard time doing both on the same year.

Aim for both but of course do it one at a time. Finish the marathon and after start training for the second. Most important is to make sure you are well prepared for each one, training, eating, etc.

I think that as long as you enjoy running marathons and it makes you happy, you should start training again for the first marathon and take it from there.  If you are already in shape and ready and feeling good about the second (which will probably be the case), run in the second one.  I think that preparing is the most difficult part of marathons, not actually running them.  If you are already prepared, why not run two?

I used to run 3 marathons a year till I was ......65! I had to stop, but that is another story. I think we may have a difference in ages, but even so, in between I did the Sydney City-Surf......(Bondi Beach) and more. But the marathon is the king of them all. Cliff Young used to run from Sydney to Mebourne.........that is some hundreds of miles.......but he was a kid of 60 odd!I had the pleasure of running with him. (Sorry if I boast!) Frank Pearson, he lives around the corner from me (Used to, he has gone to make the longest run........to meet his maker!). There are other greater challenges out there......the ski marathons. But again another story. Keep around 3 marathons a year. Don't go over the 20 mile mark in training. This is asking for trouble. These marathons I did were in the Aussie heat.

Tony Rafferty an old friend did the Sydney to Perth, thro' The Simpson, Great Sandy and Nullabor Deserts........Death Valley......so get out there and get some practise in. If I may make a suggestion.....never race against anyone.....no one! Just against yourself........you are the one that counts. Hit the wall at 20.....then no problems.