Meat can be offered to Deities. It's approved by Vedas, Smritis as well as Tantras. But only such meat that is prepared without salt and spices.
Such meat is considered as a sacrificial food or Havi i.e. food fit to be offered to Deities.
Manu Smriti 3.257. The food eaten by hermits in the forest, milk,
Soma-juice, meat which is not prepared (with spices), and salt
unprepared by art, are called, on account of their nature, sacrificial
food.
He should not eat food from which a portion has not been first offered
in the fire or given to a guest. 14 Food containing spices or salt
cannot be used for a burnt offering, 15 as also when it is mixed with
some other inferior food
Dharmasutras of Apasthambha 2.16.13-16
From the second quote it is clear that whatever a person eats must be first offered previously in a fire sacrifice (or to their Ishtas in a different context).
But such a practice (of offering prepared meat to Deities before consumption on a daily basis) is not in vogue at present. Most devotees offer only fruits, nuts, sweets, milk and other vegetarian items in deity worship.
UPDATE:
Who are these gods and manes?
Gods are the several Vedic deities like Indra, Agni, Soma, Varuna, Vishnu, Rudra, Prajapati etc..
And, manes are the Pitrus (deceased ancestors).
Manu 1.36. They created seven other Manus possessing great brilliancy,
gods and classes of gods and great sages of measureless power,
1.37. Yakshas (the servants of Kubera, the demons called) Rakshasas and Pisakas, Gandharvas (or musicians of the gods), Apsarases (the
dancers of the gods), Asuras, (the snake-deities called) Nagas and
Sarpas, (the birddeities called) Suparnas and the several classes of
the manes,
In sacrifices (Yajnas or worship) conducted in their honour, it is permitted by the scriptures to offer them meat products.
2.176. Every day, having bathed, and being purified, he must offer libations of water to the gods, sages and manes, worship (the images
of) the gods, and place fuel on (the sacred fire).
3.266. I will now fully declare what kind of sacrificial food, given to the manes according to the rule, will serve for a long time or for
eternity
3.267. The ancestors of men are satisfied for one month with sesamum grains, rice, barley, masha beans, water, roots, and fruits, which
have been given according to the prescribed rule,
3.268. Two months with fish, three months with the meat of gazelles, four with mutton, and five indeed with the flesh of birds,
3.269. Six months with the flesh of kids, seven with that of spotted deer, eight with that of the black antelope, but nine with that of the
(deer called) Ruru,
3.270. Ten months they are satisfied with the meat of boars and buffaloes, but eleven months indeed with that of hares and tortoises,
and,
5.31. ’The consumption of meat (is befitting) for sacrifices,’ that is declared to be a rule made by the gods; but to persist (in using it)
on other (occasions) is said to be a proceeding worthy of Rakshasas
5.32. He who eats meat, when he honours the gods and manes, commits no sin, whether he has bought it, or himself has killed (the animal), or
has received it as a present from others.
Regarding your other question, how can an uninitiated person personally follow these procedures for worship which are accompanied with offering of meat? It's difficult to answer.
The uninitiated person must be initiated first to be qualified to perform these scriptural methods of rituals.
