You’re welcome, @evetype. I do hope you and your togepi—or, perhaps, togetic by now—are doing well.
To answer your question, pokémon tend to give off different signals when they wish to be caught, depending on their individual personalities.
One possible signal is the tendency to want to challenge you, personally, to a battle. If the gible focuses primarily on you and isn’t attempting to intimidate you (signs of this include standing tall to make itself look bigger, baring as many of its teeth as possible, and hissing), then this is a sign that it wishes to test you and push you into trying to capture it. Engage in battle, then throw a poké ball at it. Even at its weakest, it should be able to dodge if it’s decided it doesn’t want to be with you after all.
If it doesn’t appear to be challenging you, pull out your poké ball and present it to the gible. Ask it if it would like to come along. If it seems enthusiastic by the appearance of the ball or responds positively to your question, then yes, it wishes to battle you.
Finally, if it does neither of these things, walk slowly home or to wherever you’re staying for the night. If it follows you all the way there, even after you’ve made it clear you have no desire to continue feeding it scraps for the day, then it wishes to remain by you. Alternatively, approach it slowly. If it allows you to get closer, chances are it trusts you enough to be interested in your companionship. Proceed by offering a poké ball to it.
Conversely, if it jumps and keeps its distance whenever you try to approach it, if it immediately abandons you when you make it clear you have no more food, or if it goes through the intimidation tactics mentioned above whenever you pull out a poké ball, take it as a sign that it wishes to be left in the wild. It may also be a good idea to stop feeding the gible scraps.