Basically, designing a database properly requires at least a semester of relational database knowledge. Before attempting a db design, you need to assimilate relational & design basics eg starting with docs like ...
https://www.artfulsoftware.com/mysqlbook/sampler/mysqled1ch01.pdf
https://www.artfulsoftware.com/dbdesignbasics.html
... then working through some existing designs like the sakila and world databases available for MySQL.
If device_details is the parent and device_events is the child then, based on the slim info we have, you need something like ...
create table device_types (
device_type_id smallint unsigned primary key,
device_desc varchar(64)
);
create table device_event_types (
device_event_type_id smallint unsigned primary key,
device_event_type_desc varchar(64)
);
create table device_details (
device_id int unsigned primary key,
device_type smallint unsigned,
foreign key(device_type) references device_types(device_type_id)
);
create table device_events (
device_event_id int unsigned primary key,
device_id int unsigned,
foreign key(device_id) references device_details(device_id),
device_event_type_id smallint unsigned,
foreign key(device_event_type_id) references device_event_types(device_event_type_id)
);
... but you really need to walk through the entire specification as described in the 2nd link above.