If you tell someone what you think they should do, you give them advice. Advice is a noun that cannot be made plural. You can say instead that you give someone ‘some advice’.

1. She needs sound medical advice and help.
2. I’ll give you some advice, Mike, don’t try.

Advise is a verb. If you advise someone to do something, you say that you think they should do it. You can advise someone, advise something, advise someone to do something, or advise doing something.

3. You could not help her or advise her.
4. I used to advise a simple and direct approach.
5. David advised me to try to sleep.
6. You are advised to take out insurance.
7. If the doctor foresees complications, he will advise going to hospital.

If you suggest something, you mention it as an idea or plan for someone to think about. It is not necessarily the best idea or plan; it is simply something to be considered. You can suggest something, suggest doing something, or suggest that someone does something.

8. Your bank manager will probably suggest a personal loan.
9. I suggested inviting Denny, and Jim agreed.
10. Sometimes he would suggest that she stayed at home while he worked in the garden.
11. I suggest, my dear friend, that you leave this matter to me.

Other words
Instead of saying that you suggest something, you can say that you make a suggestion.

12. I made a few suggestions about how we could spend the afternoon.
13. The other governments greeted the suggestion with caution.