Handling application data as a frontend developer - database

Question

So I'm working on building my first application in React. I really don't know much about databases, data models, schema, etc. Is it bad practice to just store my data in the browser as I develop then worry about hooking my app up to something like firebase later?
For example, below I store some user data in an object called user and just go from there. As long as I have some way of accessing it later. Keeping in mind I'm in the beginning stages of frontend development is this bad practice?
Thanks!
var SignUpForm = React.createClass({
getUserInfo : function(event) {
event.preventDefault();
var user = {
name : this.refs.name.value,
userName : this.refs.userName.value,
email : this.refs.email.value,
password : this.refs.password.value
}
console.log(user)
this.refs.signUpForm.reset();
},
render : function() {
return (
<form onSubmit={this.getUserInfo} ref="signUpForm">
<div className="form-group">
<label>First and Last Name</label>
<input type="text" className="form-control" ref="name" />
</div>
<div className="form-group">
<label>Username</label>
<input type="text" className="form-control" ref="userName" />
</div>
<div className="form-group">
<label>Email Address</label>
<input type="email" className="form-control" ref="email" />
</div>
<div className="form-group">
<label>Password</label>
<input type="password" className="form-control" ref="password" />
</div>
<button type="submit" className="btn btn-primary">Sign Up</button>
</form>
);
}
});