It definitely can be pay to win although I don't spend much on it and have good success. But I've been playing for decades and consider myself a pretty skilled player. I also use proxies, basically printed out images in place of real cards, especially for new decks where I'm not sure I want to spend money on them yet.

That said, your friend didn't give you a good introduction. Your friend should have done more to help you build a solid deck and to match the power level of his deck to yours. I have many decks of different power levels for this reason, and I think good etiquette is to bring a deck that's near the power level of your opponent's, especially if they're new.

Also, buying packs isn't the best way to start out. Probably best to have a friend build you a deck or if that's not an option or to buy a precon. Most of the cards you get in packs are bad and no one really plays with them, so if you put those in your deck, you aren't going to have much success.

Or, just decide the game isn't for you. That's also valid!

It's super fun if you're into it but yeah it takes a lot to stay on top of all the new cards nowadays.

Commander is the best thing to happen to magic though since it is a multiplayer format and it's now easier to play with friends.

Yep. Saw how much my friends were spending on it and decided I prefer eating daily meals to playing Magic.

Fair. Proxying has become increasingly accepted over time though, so as long as you clear it with your friend, that's a very affordable way to play.

Cockatrice is a free program that allows you to play MTG with friends online.

There's no way to play single player, it's strictly multiplayer. But it is a free way to play the game with someone.

I don't have any direct experience selling collections but there's a few ways you can go about it. The simplest is to go into a local card shop and see what they offer. You might want to read reviews because there is a risk they could low-ball you since it doesn't sound like you have a clear idea of the value. It might be a good idea to visit a few different shops and see what they offer, but if you have thousands of cards and don't know which are valuable, they won't be able to give you a precise value since they're not going to spend hours sorting until after they buy the collection. With old cards they can be worth anywhere from ten cents to hundreds or even thousands of dollars. So if the valuable cards are hiding amongst the worthless ones, it's hard to accurately assess value without doing that sorting.

If you have cards from the earliest editions, you may want to at least go through and look for some of the most valuable cards to exist, which are the power 9, and dual lands. You can find a list online, these are 19 cards that are extremely valuable due to their rarity and power. If you have any of these they can be worth more than the rest of the cards combined, so pulling them out and selling them separately would definitely be worthwhile.

If you have more time and the number of cards isn't too overwhelming you can also go through and enter them all into a collection manager: I use https://archidekt.com/ but there are many options. Then it will tell you which ones are worth money. Most of the value is typically in a small number of cards, and the rest can be sold as "bulk" for basically pennies. Once you have an inventory you can check with online collection buyers to see what offers you can get.

Keep in mind that when you look at prices online or in a collection manager, you'll see what cards sell for, but you won't necessarily get that price as a seller. They offer you lower prices so they can make a profit, but if it seems too low you can shop around.

Proxying is the way to go if you have concerns about cost, for sure.