no use google photos. it automatically save it for you. you can even set it to upload only on wifi to save data consumption. google drive works as well, but you have to manually do it. google photos is automatic.
as far as space goes, keep in mind that with internal storage, it is not just one big storage area. it is partitioned into segments. so only part of the 16gb is for your phone's storage. the other part is for your phone's operating system. android os now days are pretty big in size ezpecially nougat on up.
to really not worry about space you need phones with 32 gb on up.