More useful than just the solutions on the Grauniad's site is https://www.fifteensquared.net/ which has solutions with explanations of most of the UK newspaper cryptic crosswords, including the Guardian.

There’s a subreddit on UK-style crosswords that will help you with understanding clues: r/crosswords. NB that r/crossword is for the US style.

You might find the Telegraph easier than the Graun to start with.

You just need to ask someone /read guides about solving cryptic crosswords. Once you get used to it, it makes sense, but there can a surprising amount of 'unofficial' knowledge (abbreviations, 'common' crossword answers, etc), or things which are uk-specific and are not straightforward if you're not from the uk.

Some compilers are also easier than others / will make more sense to you (I like brendan, nutmeg, vulcan, and philistine).

May be the Guardian one needs a Chambers dictionary to solve it?

But still, is there a good guide to get into Cryptics?

Cracking the Cryptic, e.g.: https://youtu.be/ecytVCusIeY

It's mostly a variant sudoku channel but Mark Goodliffe is an insanely good cryptic crossword solver, and both Simon and Mark are good teachers.

Beyond the intro the key skills are: parsing the clues into definition and wordplay, knowing signifiers for different types of wordplay, recognising common abbreviations (there are lists a web search away), recalling short synonyms, and anagramming.

If you want to get your mind blown I highly recommend spending the $2 for Cracking the Cryptic's Patreon to watch Mark solve the Monthly Club Special using almost pure wordplay and whatever string manipulation coprocessor he has in his head (which also seems to work for sudoku too).

That youtube channel seems to have veered into mostly Sudoku style puzzles than Cryptics.

Yes I said that. Still -- many, many hours of cryptic crosswords being solved and explained if you want to see how the best in the world does it.