ANY COMMENT IS FINE
The best advice I can give you is to prioritize your main objectives in game first. Some people really like to max their scores in Guild Boss, some like Battle Royale, some focus generally across the board for Lords League and Guild Clash, etc. Once you identify what strength you wish wish to prioritize, spend on skills for the main heroes that help you progress in those areas and on the best hero aids you can support.
Do not spend on hero skills of outdated heroes or non-essential hero aids.... Some good heroes to focus on are Abyss, Toxic, Amber, Won Ton for dps or aid, Wolf for tank or aid, up to 5 Zerker for aids, Enchantress for main or aid, up to 5 pan for aid/dps, arcane caster, sage for rage generation/silence, maybe two blockheads for aid, rath for hero kill/control or aid and landslide for tank. There are others to be sure, but these are all good.
Do not spend rings buying heroes...