Hi, dont worry about being new, the main point of using a cheat that is completely external rather than internal is the fact that it doesnt mess with the game files and remains mostly undetected.
There are many cheats/different types of cheats out there, let me explain a few.
1. COLORBOT a colorbot is a cheat that exploits valorants outline, think of it as a bot that just aims to the color purple, yellow, or red. Most cheats in the market use this kind of software mainly because its the hardest to detect, its completely external from the game itself and just aims at pixels, doesnt interfere with the game at all, however these can still get detected, there are a few good ones on the market, just go for the ones that are the most vouched and seem to have the most positive feedback.
2. ARUDINO An Arduino cheat is extremely similar to a colorbot, matter of fact most of the time they are colorbots, the only difference with this kind of cheat is that the mouse movements are simulated on an Arduino instead of your own pc, sometimes these can be more secure and better than software cheats, but this should only be a last resort when you are extremely worred about security. Buying an external piece of hardware, soldering it, and then plugging it into your pc to cheat is pretty risky.
3. ESP Esps are pretty dodgey, most of the esps that are even relatively good require ID verification and usage of other cheats. DO NOT BUY PUBLIC CHEATS Why? Because all of them are simply detected, any cheat that does not have any real value to it and is easy to buy is almost certain to be detected garbage, avoid any resold cheats.
4. RADAR This is a different type of cheat, these are usually pretty difficult to get a hold of but once you can get a good radar you will be set, most of the time a radar cheat requires two pcs to properly run, one pc will show the radar itself and one will be playing the game, this is especially good if you have a laptop that can sit on your desk while you play valorant, of course the cheat is completely streamproof because its being rendered on a different computer. The only downside is that a lot of these cheats are rediculously expensive.
NOTE: Vanguard is an extremely extensive anticheat, probably one of the best next to faceit, its important to state that all cheats can get detected, thats exactly why you want to go for the ones stay undetected. Even if you come across a really good ud cheat you can still get destroyed by reports from bumhurt hardstucks. Cheating in this game is difficult and if you dont know what you are doing, you can easily buy a crapware and destroy your chances of ever playing valorant again.