Picks:
Personally, I would aim to have some coverage in N. America and Central Russia/East China. This is because these areas have great expansion opportunities in the short term and long term. I would consider Antarctica as safe income - Australia is too big to have an isolated pick and Central America is more favourable to South America.
Wastelanded bonuses are out of the question (unless you have a exceptionally good reason to pick them). Inefficient bonuses are also out. By inefficient, I mean a bonus of 5 (for example) territories worth 3 (for example) when there are bonuses of 5 (for example), territories for 4 (for example).
You need a mixture of good expansion opportunities and safe income.
Turn 1:
Don't attack neutrals of value 2 with any less than 3 (assuming normal kill rates). Doing so wastes an army. The attacker kills 1 defender and the defenders kills 1 attacker. You'll later need to attack the 1 with 2 to capture the territory. This will 1 kill more attacker and the defender. In contrast, a normal 3v2 would kill 1 attacker and allow you to capture the territory. See
https://www.warzone.com/wiki/Combat_basics for details.
Turn 3:
Why were you expanding to Indonesia? You already have 1/5 of East Africa, so you should capture Sudan in order to complete it next turn. New bonuses have a 4 neutral in there, the East Africa doesn't have one as you picked a territory in that bonus. New bonuses take more armies to complete and a longer "pay back time".
Turn 4:
It's very unlikely that the opponent is in Antarctica (if you attacked South Africa with 6 in anticipation of the player being there). In general, Antarctica isn't a key area. Would have been better off completing East Africa and then hitting Brazil/Venezuela in 1-3 turns with a large stack.
What is the army in Beijing doing? Unless you're planning on expaning into West China, there's no point in leaving it there. It's better to move it in the general direction of Japan (without taking Korea as that territory is invaluable; Japan can act as a counter attack on N. America).
Turn 5:
Attempting to complete South Africa is inefficient. South Africa has 5 territories and worth 3 while East Africa has 5 territories and worth 4.
Going almost all in on expansion is a poor decision when bordering an opponent. You need to be able to defend from a potentially large stack + deployments. You should only spend 1-3 armies on expansion and defend with the rest to have a good compromise between expansion and defending. When expanding slowly like this, only take 1 bonus at a time to prevent the opponent breaking through.
Attacking your opponent the first time you meet them is a bad idea, as you could be doing an inefficient attack. You have no clue of what their income is unless to do deep analysis of the potential picks. You should use the Analyse Attack function under Game to see if attacks are worth doing. You could also take a look at
https://www.warzone.com/Forum/386978-ujs-luck-graphs-script and
https://danwlgames2.000webhostapp.com/WL_WZ/WL_calculate_attack/WL_calculate_attack.html to have better analysis of attacks
Turn 6+:
The game is lost from this point.
You're welcome :)