Hi,
Be aware that if you buy a brand new 2M ARF F3A-plane many of them come with very little or no instruction how to set them up. The manufacturer assumes the buyer is experienced and know the basic how to setup and trim a plane from the scratch. That is a challenge for a beginner. and can also be for a more experienced F3A-flyer. If You are willing to listen and learn and take Your time that can work, but I think I would spend money on a plane thet is known to fly very good out of the box and not much need for trimmimg incidences (stab, wing), motor direction and such that can be little tricky to dial in correct. There is even some company (in US) that offer (or at least has offered) basic setup (according to designer preference) of a new 2M ARF from his company at additional fee.

The fastest way to get up in the air is to buy a second hand 2M F3A plane from an good and experienced F3A-flyers that has set up the plane properly and used it rather much then at competitions. Usually electric 2M F3A-planes are almost like new also after many years of usage.

And do not forget the slightly smaller seize "125" ARF F3A-planes, some of them are very capable and do not cost as much as 2M ARF F3A-planes.
Personally I had a MythoS 125E (white-blue-red) when it came. I have Hacker A60-7XS (version2, it is version 4 today) motor, with 8 cell 5000 mAh LiPo and Falcon 19x12 Electric carbon V2 prop. It flew (and still fly) beautifully out of the box. The throws on all control surfaces I have to my preference of course, and CG also. When I some years later wanted a 2M F3A-plane I sticked to same manufacturer and got a 2M MythoS Pro with Hacker Q80-14XS, 10 cell 5000 mAh LiPo and Falcon electric carbon V2 20,5 x 14.5. It was little more work to assemble MythoS Pro becacuse mounting the motor is more work. It has adjustable stab incidence (needs to be adjusted), but fixed wing incidence (not needed to adjust). I flew for several years both MythoS 125E and MythoS Pro in FAI Adanced class (named F3A-Nordic up here in our Nordic countries).

After some years it was time for a new plane and this time I wanted to try a top model, so I bought in 2015 (delivered in beginning 2016) a Galactika EP (electric) and assembeled it during spring 2016, and started to fly FAI F3A class. It was much more work on this plane then the previous planes I had. I have a Hacker Q80-14XS here also but with Falcon 21x14 electric carbon V2 prop. First I had 10 cell 5000 mAh LiPo but after some minor repairs and reinforcements it was little too heavy so I changed to 4600 mAh Lipo (that I still use). I had to move the rudder servo from tail to front in fuselage also to get the CG correct. This plane has both stab and wing incidence adjustable from factory. It was rather much trimming of the plane in the air before I had incidence and CG as I wanted it so it flew good. But I learned alot during thie process. I hade great help of reading Brian Heberts trimming infomation he has written on his homepage and I also bought his Trimming Guide that contain more info. Trimming an F3A plane to near the plane capabilities is often the key to fly really good in F3A, so time spent on this is well worth the time and effeort needed. Then one can concentrate on flying the manouvres as good as one has ability to. Then You know basically that the plane is not the limiting factor. It is so easy to fall into the thinking that with a another new plane I will fly better, but probably for most of us that is not true. At least that is my believe. I have flown my Galactika EP now for 4 seasons and I'm not sure I have it dialed in the trimming to it's full potetial yet, but it flies so good that it is not the plane that set the limit, it is my own capability for sure. For me I have no possibility to fly more then 250-300 flights per season so to improve by increasing flight time is not possible for me. I have heard some top pilots do maybe 800 flights per season but that would be impossible for me. So better quality when flight training could be one way to improve for me. In my case it would mean have an experianced F3A-flyer watch on a regular basis my flights to give feedback on what to improve. I'm more or less blind to what I migh do wrong and need to improve since I fly the FAI F3A P-Schedule 99% alone (I do not practice Final, F-Schedule).

Some help on the way on ESC: in F3A-flying we most of the time fly at around half throttle exept when a manouvre demand more power (or less). This half throttle Power actually put more stress on any ESC than at full power so it is more likely to get failure on an ESC at lower throttle then at full throttle. Some ESC are not designed for F3A style of flying. I know of own experiance since I burned one "90" (amp) ESC of a known brand myself in my Galactika EP during half throttle power. So pick an ESC that is known to cope with F3A flying.
And do not be afraid to adjust the break on the ESC, it realy help on downlines to have an efficient break active in ESC so prop will be able to give a break effect. I flew several seasons with break set to low perecntage (56%) but after some tests later I have now 90% and it is more efficient. I could just not think I would need that much break power percent on the ESC I use (Master Mezon) with my Galactika EP.

In later years F3A biplanes has been more popular. From same manufacturer as MythoS Pro You have the PromethoS biplane. I have seen it fly at competitons and it flies great. The person that has it here in my country has won our nationals twice with it in FAI F3A class. He use Adverrun Contra in his plane. No modifications as far as I know from stock. Wing incidences fine from factory. I think he use 5000 mAh LiPo.
It could be worth investigate if such plane would suit You.

I have some assemby info on my MythoS 125E, MythoS Pro and Galactika EP on rcgroups F3A pattern forum (on the MythoS planes) and here at rcuniverse in Electric Pattern Aircraft forum (on Galactika EP) if You want to know little more of my assembly.

Good luck.
/Bo