Alright so here is first, Valorant T1 is divided into 4 region that all have the same number of spot in every Valorant tournament Asia-Pacific (APAC), China, Americas, Europe-ME (EMEA)
Year start with a double elim to qual for the master right at the start of the year, then we've got one split and the mid-master, and then a second split that qualify to champions.
Every region have 10 franchised team Americas have 5 NA, 3 BR, 2 LA. Europe have 7 EU team, 2 TR team and NAVI (That is CIS or Europe depending on how you classify Ukraine), APAC have 3 KR team, 2 JP team, 4 team from SEA (TH/MYSG/ID/PH) and GE that is supposed to represent India but got almost only import. China have... 10 CN team (Even if you can argue WOL and historically DRG may represent TWHK)
Each region have 2 ascended team that come from T2, thoose are the only team that can be relegated.
If you really want to dig into Val and learn about T2 the world is divided into several subregions
- EMEA : France/Spain(+IT/PT)/North/East/DACH/Turkey/MENA (Divided into Levant-north-Africa and GCC) And I bet Subsaharia migh be a thing in the future
- APAC : Korea/Japan/SEA/Oceania/India
- AMER : NA/BR/LA (Divided into LAS and LAN)
Any team can qualify to T2 region playing premier, that is basically T3, it's a tournament that is integrated in the client that take place any week and with promotion every 2 month.
They are also a fem tournament called GC (Game Changers), with decent team that is close to qualify into T2
About role every team have at least a duelist, a smoker, a reveal, usually a sentinel, and another player that is sometime called flex (but I hate that term, this 5 player may not have a big agent pool, some of them may even be "One agent player" in some metas), this last player usually plays initiator flasher or smoker like viper and sometimes both. The awaper is usually the duelist and the entry, the lurker is usually the sentinel. Some player like to switch role with other player of their team sometime, role are not totally fixed.