If you’re talking about food and drink, you can use the verb prendre” to mean “to have”. If you think about it more as being like “intake”, you can imagine that when you eat or drink something, you take it into your body.

au petit-déjeuner, je prends des céréales et des fruits
at breakfast, I have cereal and fruit

je vais prendre un café
I’m going to have a coffee

j’ai pris une boisson et un biscuit
I had a drink and a biscuit

veux-tu prendre un verre?
do you want to get a drink?

If you’re ordering something to eat or drink, a really common way to do it in French is simply to say, “je prends…” followed by what you want. It literally means, “I take…”, but it’s a very common way to order.

moi, je prends un vin rouge, s’il vous plaît
I’ll have a red wine, please

Or, you can also say, “je vais prendre…”, which literally means, “I’m going to have…”

je vais prendre le poulet
I’m going to have the chicken

je vais prendre le plat du jour
I’m going to have the dish of the day

In English, we can use the verb “have” as a way of saying that you’re eating or drinking something:

I’m having a glass of wine
I’m going to have a pizza
I had spaghetti bolognese last night

In French, however, you cannot use “avoir” to mean that you’re eating or drinking. Either you can use the verbs “manger” (to eat) or “boire” (to drink), or, as we discussed above, you can use the verb “prendre”, which literally means, “to take”.

je prends un verre de vin
I’m having a glass of wine

je vais prendre / manger une pizza
I’m going to have a pizza

j’ai pris / mangé des spaghettis à la bolognaise hier soir
I had spaghetti bolognese last night

If you’re not talking about food and drink, however, you can use “avoir” to mean “to have”