Difficulty pronouncing words with f and p

Top teeth on bottom lip, bite slightly and breathe out. That is /f/. No teeth on lips. Push them together. Breathe out such that the breathe pushes the lips open to escape. That's /p/. You will have to consciously think about it for a very long time every time you want to make the /f/ sound because it isn't a part of your L1 sylabary. Maybe years. I have Japanese friends that have been in the US for a decade and still have to consciously think about l/r. It is a similar thing with Tagalog and p/f.

Practice these sounds in isolation and then slowly try to say them in words and sentences

The F sound is made by putting your upper front teeth on your lower lips and make sure your upper and lower lips don't touch. If your lips touch, it's impossible to make the F sound. The opposite is true for the P sound. It's made by touching your upper and lower lips together. If your lips don't touch, it's impossible to make the P sound.

/f/ and /v/ are both produced by placing your top teeth against your bottom lip - think of biting your bottom lip - and letting air stream out between your teeth and bottom lip. It sounds like air escaping from a flat tire. The only difference between the two sounds is that /f/ is voiceless while /v/ is voiced. /p/ and /b/ are both produced by closing your lips tightly, pressing air against your closed lips, and letting it out in a sudden burst. It sounds like a tiny balloon popping. Again, the only difference between the two sounds is that /p/ is voiceless while /b/ is voiced.

typical PFBV issue for some Filipinos. Chances are, you might also have a TH issue. Your vowels might not be that great either if you think "full" and "pool" sound the same. DM me if you want to be assessed.

Practice minimal pairs so that you can get used to the distinction. This allows you to train your ear to hear it better as well as gives you a chance to practice pronunciation differences. Since /f/ and /v/ (“of” ends with /v/) are fricatives, they can be held out, so practice words with them by holding out the sound as long as possible. Over time, you can reduce this duration. Don’t worry about fast speech right now. If you’re trying to work on pronunciation, you have to start slow. As you build your muscle memory for English pronunciation, you’ll be more naturally able to speak quickly correctly.

I've heard from Asian communities that singing karaoke in English helps with pronunciation. Otherwise I'd just assume it's a language barrier for pronunciation due to your language not having the F/P sounds. If I can understand what you mean, pronunciation doesn't really matter "I went swimming in the fool." Oh cool how was the pool? Was it heated?

A lot of different languages have "tongue twisters". they are phrases that are difficult to say because of repeated sounds with small variation between words. The are often used in helping children learn to control speech or for actors, singers and public speakers to warm up before a performance. For the "p" sound, a famously difficult tongue twister is: Peeter piper picked a peck of pickled peppers. Or just make up your own to practice the mouth shape of the sound: Forget fists, let's food fight, friends. Or practice going back and forth between sounds: Party food, food party, party food, food party.

I don't know, it seems to me that it would be hard to get these sounds confused. /p/ requires closing the lips and /f/ requires keeping the lips open. I guess all you can do is keep practicing.

FYI the consonant in "of" is /v/, not /f/. And the vowel sounds in "pool" and "full" are different. "Pool" is /pul/ (rhymes with "fool"), while "full" is /fʊl/ (rhymes with "pull").

Minimal pair practice. First, get a native speaker to record minimal pairs for you (there are several places online where you can have native speakers read something for you for free). Listen to those minimal pairs over and over until you can distinguish them. Then, record yourself saying minimal pairs until you can distinguish them.

To pronounce an English f, your bottom lip touches your top teeth. An English p is made with the lips touching each other. Your post also makes me want to point out that full, pull, fool, and pool are all English words, and pull and pool do not sound the same. So you might need to work on your vowels too.

Out of curiosity, what’s your native language?

You need a speech therapy