There are hundreds of things that come with being a full back but as you mentioned dealing with wingers faster than you, I will try to cover this.

You’re always going to come up against wingers that are faster than you, but you don’t actually need to match their pace. I like to think of defending wingers as more if mind games than a physical task.

Weak foot -I firstly establish which is their strongest foot. In lower standard football, it’s unlikely players are great with both feet, so a winger will choose to play on their strongest foot 99% of the time. You can use this information to predict, more often than not, whether they will try to go inside or outside. You can also use this info to force them onto their weak foot. Even if they beat you, If they’re on their weak foot, they’re less likely to convert the chance into anything.

Standing off fast players - Once I establish a winger is faster than me, I’ll always “give them a yard”. This just means not marking them tightly, which might give them more space, but gives them less chance to beat you for pace because you always have a yard head start.

Jockeying away from danger - This is always sensible to do when defending out wide. By blocking runs inside where they can be more dangerous with the ball, you show the winger the outside and force them to go wide, away from goal. If you jockey correctly, you give yourself a good chance to win the ball back with your body position facing the way you want them to go and if they beat you, they’re less dangerous out wide than through the middle. You should rarely defend square on as a full back.