I have frizzy and dry hair so I'm gonna use hair gel but do I have to wash it off every time e.g. daily (I'll probably put it on daily) I put it on? If I have to wash it off then should I use just water as I have dry hair so I think shampooing my hair daily will make it more dry? Help me!
It depends on the particular product and the amount of it you use. Daily washing would probably not be good for your hair type.
You could look into using products like curl creams which are a little lighter and work better for less-than-daily washing. I use a leave-in conditioner that my stylist gave me, Devacurl's Frizz-Free Volumizing Foam (I use just a tiny bit of this on my hair while it's dry, which isn't what the label says to do) and various Bumble & Bumble sprays every day and get away with washing infrequently (I hate clean hair).