G’day / Yuuma! Welcome to postcrossing!
You could check your preferences so you’re able to send to your own country. (I deliberately ticked overseas only as I send a lot of cards domestic post.)
Do you have permanent/waterproof pens like say pitt artist or copic multiliner or Unipin or Sakura to write the address? Mail to a different hemisphere could mean flooding or saturated mailbag and no address for the post overseas to read. (I write the whole card in waterproof pen but that’s just me.)
Do you have any sites for international phrases bookmarked? I always greet and introduce myself in their language where they’ve a different language to English listed. Yes I realise they want to practice their English but… I want to practice my foreign language skill too. Prevents the panic of “how do I do that for a Finland person” and finding that Suomi is what should be used.
What’s the cheapest way to send your cards overseas? You are jumping into what could be an expensive hobby in just postage and postcard costs alone. (In Australia it’s maxicards, then international specific stamps to make up the 3 zones of overseas postage. Domestic stamps are more expensive again because you have to use more of them- it’s our tax system 
.)
Write your family some postcards! Even if they’re in your town you may not have seen each other in a month. Or more if you don’t remember the date you last saw them 
By all means swap via the forum but there are some folks out there that won’t send your item in return. That can be very upsetting especially because they may be doing this to other postcrossers. (I didn’t start direct swaps until this past week and only when I saw the people I’m swapping with have been postcrossing and direct swapping successfully a long time.)
Online shop for postcards- warning this will be addictive if it’s local artists or even your local Etsy
Remember that COVID19 has hit post really hard. So what used to take 14 days (the US and UK from Australia pre COVID19) now can be 30 to 60 days… or longer again. Also beware that some post will go missing. I’ve had 3 cards leave here at the same time for the same overseas country received in 14 and 16 days - but the 3rd took over 200 days. I’m glad I wrote the date on it because they didn’t believe it took so long based on the postmark and my date mark. That’d make two of us 
Finally enjoy the process- before you know it you’ll rack up the numbers.
Enjoy post crossing and stay healthy!
Yerrabi / bye!
There’s a going rate for US and a going rate for international so I have stamps for each zone, but in a pinch I’ve used two or three permanent stamps to cover the postage (which is more fun as permanent stamps are the ones with cool designs!)
I didn’t feel brave enough for tags until about 18 months later, and it took me 4 years to venture into a round robin, I really struggled to understand both. I do very little tags and RR as I prefer officials and penpals/postcard pals. Officials have the surprise element, and regular relationships are fun because you make friends.