First of, for someone supossedly new to the game (rank52) you seemed to manage pretty well against these 2+ prestige guys. The skill difference was probably the biggest reason to lose but there is no shame in that, now onto the game!
You send your first two grens to fight around the road betweent he middle vp and right munition, this is not a good place to fight and especially not for grens. You did realize your mistake but if you would have sent support to your pio right away to the right you would have more mapcontrol
You generally floated ~80 before actually making the unit you want, early game timing for units is quite important as the early skirmishes set the tone for the rest of the match. Try to decide what unit you want before you have the manpower so you can spend it immediately
I think a 251 HT would have been much a better choice. all hte m3s were dead and you likely wont catch a sniper with the 221 on this map un less you're really lucky. Instead a 251 HT allows you to push and creep up your grens + mg while keeping all your units on the frontline.
Losing a MG42 is quite a devastating loss and you should try to recover or steal it back as soon as possible
As you said you definetly teched to T3 too soon. You had no fuel for any T3 units yet and with the mapcontrol at that point it didnt seem a good option. due to the call in system in COH2 you generally want to tech as Ostheer and Soviet only when you're ahead or ahead and want to force the enemy to get units they dont want. In your situation your mapcontrol was bad and your fuel at that point is better saved to call in a tiger/elefant or tech later on when you have the fuel. A pgrend have definitely helped
At 13 minutes in you sent your grens to right again from the base while you would have probably been better of getting the left under control. in 2v2 you must be very careful of not getting tunnelvision and playing seperate 1v1. Road to kharkov espeically it is important to have your native fuel and cutoff under the control. The other side is less important but ofcourse still crucial to harrass, but not with your whole army.
You then see why mg42s are so crucial not to lose if you have your grens blobbed like that. always try to spread them out espeically when you know he has an mg42 and there are mines (or demos)
I dont really get why you would get a Ostwind, you were behind and the opponent at your side had more fuel most of the time but no vehicles built. Meaning he will get call in tanks which will wreck your ostwind. in 2-3 cps. An ostwind is a good choice if you are ahead and want to punish your opponents for waiting for callins
For your teammate (as it seems you're a team) a Flak HT is a very good unit to get against soviet t1 and conscripts as it allows you to hold the line quite easily, but you want it call in aroudn the 6m inute mark, not 14 minutes in the game. the Scwere HQ was also in a weird place. Yes it covered a flank but it was relativly exposed and would have served much better around the fuel protecting somethign important
Both of you then switched to the right side, which can work but it left the mechanized truck undefended.
I, among everyone in this community, gets owned by mines. Its a matter of reducing hte chanche of that happening by getting a sweeper soon and always have it around when charhing in territories youve seen engies or that has been under enemy control for long.
Hope this helps you in your future games