Understand that in most British accents, speakers don't roll their Rs (except for those from Scotland, Northumbria, Northern Ireland, and parts of the West Country and Lancashire), but not all British accents are the same. For example, a Scottish accent varies greatly from an English accent.  After a vowel, don't pronounce the R, but draw out the vowel and maybe add an "uh" (Here is "heeuh").  In words like "hurry", don't blend the R with the vowel.  Say "huh-ree".  In American English, words ending with "rl" or "rel" can be pronounced using either one or two syllables, completely interchangeably.  This is not the case in British English.  "-rl" words like "girl", "hurl", etc., are pronounced as one syllable with silent R, while "squirrel" is "squih-rul", and "referral" is "re-fer-rul". Some words are easier to say in a British accent. For example, mirror, which sounds like "mih-ra". Do not say "mirror" like "mere"; British people almost never do that. Some awkward pauses in sentences are also removed by the addition of "r" before a vowel. For example, "I saw it" becomes "I saw-rit", to avoid the pause between the words 'saw' and 'it'. Another example is "Bacteria are small", pronounced "Bacteria-rar-small".
تَعَلَّم نُطق حرف R.