DPoS Reward Schedule
Block 0 - 2400 = 100 Coins
Block 2401 - 4000 = 1000 Coins
Block 4001 and Up = 50 Coins
Is it normal that my first stake was 50 GOAT?
Yes it's normal. Wallet shows you staked 100 Goat but you get 50 goat because of the Herds, they got the half of the stake.