If your new than this will help. Those who been playing more than a year see if I missed something....

Starting new:

When starting new, you want to complete the easy campaign first. You don't need to do ladder battles first. Once completed, you can complete the ladder battles. Save SM credit and Tokens as much as possible. Once you get to level 30, that's when to buy boxes and use SM credit and tokens. (It was better 6 months ago.) Anyway, do not use the free tokens until you reach lvl 30. It's a smart thing to take into consideration. Battle in the Latter battle rather in chat. It will take longer getting to 50 in Ladder Battles, though worth it. The ladder battles do not get erased, yet chat requesting battles do. It may take longer, but doing it in the ladder battles is better. Using your tokens is a risk when new. Do you want to continue the campaign or risk your tokens on special boxes!!! Do the math, and think about it. You will have about 200 or more tokens left if you complete hard or insane campaign (I don't know if it change, but that was 6 months ago. It might be different). So the decision is on you, when you get all tokens. Try to complete "ACHIEVEMENTS" as fast as possible. You get more SM credit and tokens.

Heat Mechs:

When I was new, I didn't know crap about this game, especially heat or how to build a mech. Now is the time for this game to take in consideration that you will always have a 3v3 battle against a heat mech, especially rank 3 through 1. Now here is your advice when battling a heat:

Try to make cooling regenerate 100 or more, better if above 115. If you don't take that into consideration, you already lost. I battle New players who didn't do this, and their cooling was 15-35. Use shotguns, if you have them. If you get "LUCKY" and get a "Firewall" for free, use it.

Now for energy:

Just like battling a heat, you want to regenerate energy also, if your weapons have energy consumption. To build the best mech against an energy is a physical resistance mech, with weapons that have no energy consuption. Yet, there is a negative to this, when energy drops to "ZERO 0," that is where energy mechs get the upper hand. The energy weapons do almost twice the damage at that point. (Something I didn't know when I was new.)

Now Battle pads or whatever they're called:

I didn't know this either, yet each pad has a positive and negative depending on the mech. Physical pads up the damage for physical weapons, energy pads up energy damage for energy weapons, and heat pads up the damage for heat weapons. Cooling and energy pads up your regeneration for heat and energy bar. Then there is Resistant pads. These pads can be a negative and positive. They take away resistance, if you have any. If you have negative resistance, they take away the negative.

Building a mech:

When your new, and just started, you can basically throw on any weapon because you really don't have much that go together. Yet, when you get to rank 3-1, you want to take into consideration of building a mech that have the same "weapon that do the same damage." When I mean the same, I mean heat damage, energy damage, or physical damage. Put only heat weapons if your building a heat, only energy weapons if a energy, or only physical weapons if physical. If you can't build a mech with the same weapons that do the same damage, try to make it the same as possible. I see this a lot, don't just throw on weapons that can't fire each distance. Each weapon has it's own distant to take into consideration. Try to use each weapon that covers a certain distance. A mech does not need all 6 weapons, because you basically are not going to be using each one in a battle. I say 4 weapons at the most. Upgrading is another factor in mechs. Upgrading takes a help in each part of you mech.

If missed anything, post it. My mind went blank typing all this....

Me like this.
And, true, "it is best to have pure type Mechs", except for he who is with 3 or 4 years of experience/ experiences.

I did see several Mechs equipped with2 or 3 melee weapons , and "what the ...." asked myself.

Also to add on the heat mechs section,

Use as less heat as possible when battling other heat mechs. This way, you will be less likely to lose both of your action points due to your opponent's weapons. You would not want to give your opponent the upper hand by having your heat over it max capacity. Your best bet for this method is to use legs such as magma barrier or flame boots. That way, you can increase your opponent's heat without using heat.

Acquire latest op myth.

How?

Loool

Credit card, lol. That's the wack way. The lazy way. If you want to be come great, than learn the game without paying. I have not yet spend here, and still rank 1, what you do spend $$$.