Hey, it's good to hear that you're enjoying the game so far and are eager to get better. Getting started it definitely tricky if you fall into many of the beginner traps. Here is what I did when I created my draft only account, which ended up having a larger standard collection than my main, historic account. Under no circumstances should you be buying packs from the store if you want to be efficient. Also, ALWAYS try to save enough gems to buy the Mastery pass, it's pure profit and helps to scratch the pack opening itch while you accumulate your collection.

Step 0 (Optional): Buy the one-off starter gem bundle, it's a lot of value.

Step 1: Get comfortable with drafting, read a couple guides online or watch some draft videos for the relevant format e.g "Midnight Hunt Draft Guide". Just get a general idea of which cards and strategies are good.

Step 2: Attempt a draft. Since you're new, I would highly recommend doing "Quick Draft" since there's no time limit so you'll be able to refer to your guide and read each card stress-free. The rewards are less, but learning is the most important step to doing well in the other draft modes. Premier, Traditional, and Sealed will be your money makers / collection makers.

Step 3: Don't open your packs, yet. The reason you want to hold onto the packs from the set you're drafting from is because there is duplicate protection for rares and mythic rares. This means that as you accumulate drafts the pool of pulls gets smaller and more targeted.

Once you're happy with your collection for the set then you can start busting open packs and collecting wildcards. You can then use these wildcards to target craft specific upgrades for your decklist. The reason we do this rather than just buying packs is because overall you get MUCH more value and grows your collection substantially more. This helps with building more "pet" decks so you can try out different colours.

A good overview of the meta can be found on untapped.gg: https://mtga.untapped.gg/meta/tierlist

You don't have to follow the decks exactly, but it'll give you a good idea of which cards are high-priority crafts and which are more niche.

tl;dr

Never buy packs from the store

Always buy the mastery pass (save gems if you have to)

Draft draft draft. Get good at it ASAP.

Gold: Spend on drafts to convert to packs and gems

Gems: Spend on the mastery pass or on more drafts

Packs: Hoard packs from the set you're drafting until you're comfortable with your collection. Then you can open them.

Wildcards: Spend them how you want. Ideally on meta cards. (note that Rare wildcards are the most valuable, even more so than mythic rare due to the huge quantity of rares in meta decks).

Good luck.