Can I start by commending you on your attitude? I love that you want to be a great lover and will even go as far as to 'take lessons'. As you get older, you will realise that this is what separates those who are winners from those who are average.
Now, you will learn to have sex and specifically how to please yourself and your partners with practice and an attitude of curiosity and playfulness (which you seem to have). Might an older lover help with this? Of course. But are you even attracted to older women? Or would this merely be something to do because your friends said so? And keep in mind that not every older woman is great in bed or a great teacher.
We are usually attracted to people who are similar
We all have what we are attracted to, and for most of us, that is usually people within our age group, income bracket, and even aesthetic bracket. There aren’t many couples with huge age gaps, money gaps or gaps in looks because, for the most part, we tend to be comfortable with people who are like us. Chemistry plays a huge role in a sexual relationship and you will be better off finding a playmate who you are madly attracted to and feel comfortable with – and then going from there.
Ignore your friends and have sex with willing partners who you are attracted to...
Great sex isn't about age
Great sex demands that we not be self-conscious around our partners so that we can let our guard down and be naked both physically and emotionally. Who we can achieve this with is not always obvious, but physical attraction is a great indicator at the beginning. This is why I am suggesting that you ignore your friends and have sex with willing partners who you are attracted to. If she turns out to be older that’s fine. If you are age mates then that’s fine too. Just have fun.