Where to buy tickets?

Question in title, taking my father for his birthday but it’s been a while since I’ve bought tickets for myself. Do I buy the the mlb app/website ? Seat geek? Vivid seats? Looked on all three but the mlb website doesn’t have much seat availability as the others. Sorry if this isn’t the right place for this.

Also to hell with service fees 😡😤🤬

And where do y’all prefer to sit ?