Please Help me make a better servant team

1. Raise Mash. She tries her hardest and won't let you down.

Your current servants are more than sufficient. Ozymandios, Nero, Atalante, Cú, Caster Liz, Beowolf and Emiya are all quite good at their roles. Raise them and use them against the appropriate enemies.

You’re same as me when raising everyone at the same time :D. There is a formula for almost every battles :

Carry (pos1) +
Waver/Meme (pos2) + Han/Mash (pos3) and pos4,5 are backups/additional buffs, pos6 is lastman standing.

I see you have ST and AOE servants of each class so all you need is to level up them. You could raise some supports for particular attributes such as Shakespeare for Burst, Mozart for Arts and you already have Atalante for Quick. Some tanky servants like Georgios, Leonidas are good too.
Mind you, there’ll be event in the New Year that doubles success rate of ExP cards, thus waiting for it. Gl

Generally a good team is made up of a damage dealer(ex Ozy, Cu, Atalante, Nero etc.) support( Hans, Mash, Waver, Merlin) and depending on what kind of team you’re making, another support or a crit star generator(Cursed Arm Hassan, Emiya Assassin, Jack the Ripper). There are various types of teams you can make and each has their own advantages and weak points. For your selection it seems you’d work best with either a buster crit based team(mainly because you have Ozy who is an amazing buster crit damage dealer) or an arts team(Nero and Emiya Assassin are both arts servants.
Some team ideas:
-Ozy, Emiya, and a friend’s Waver or Merlin
-Nero, Mash, and a friend’s Tamamo or Waver
-Cu, Mash, and a friend’s Waver or Merlin
-Robin Hood, Mash, and a friend’s Tamamo or Waver
Really don’t stress about team comps much though as that stuff really only begins to matter later on in the game once you’ve gotten used to it and have a wider pool of servants. As for servants you should look out for, really anyone you can benefit from at this stage since you’re still early on into the game. Just look into banners and figure who you like and save up for them. We’re behind Japan by 2 years so we can see who’s coming out the upcoming year. Here’s a site that has a lot of that info in particular: https://grandorder.wiki/Upcoming_Summoning_Campaigns_(for_EN_reference)
Hope this helps!

For now, don't worry about team comps. Just use class advantage. Raise your most used servants to at least 3rd ascension and get their skills up to around 4. In addition to the servants you have, try raising from the following: hans, medea, leonidas, georgios, and kiyohime. You can always borrow a friend support to see if you like using the particular character.
If you do want to build a basic team comp, try using servants with a similar deck. For example:
Buster would be ozymandias beowulf yuushaliz.
Arts, nero emiya, david.
Quick is atalante cu billy.

I totally agree with haagen when first starting out just use generic teams that are just type advantage... ozzy is definitely an all star in your line up so definitely show him some love, nero isn't bad either... beo in most of your comps could be your primary damage dealer... with mash as a defense support and if you have hans/zhuge/merlin then that could also be a good fill if not id borrow as a support to help make your team stronger... that's what I did and it got me pretty far til I could stand more on my own and don't feel bad if the support servant is a carry it happens if you have like any of those good supports I already mentioned you could go mash, insert another support and then borrow a good damage dealer from a friend... those are your best options at the moment

In my opinion a more consistent all around team should be built around a berserker since they are effective against all classes (except shielder) currently present in NA. It also saves you the trouble of making a different team for each different battle.

MAIN DPS's:
>>Beowulf is an excellent ST berserker for boss killing. Equip him with any CE that gives a starting NP of at least 40% and that preferably gives purely attack bonus, (e.g. MLB golden sumo, MLB Holy Night Supper, Kaleidoscope)
>>Kiyohime (for farming)
>>Darius III (for farming and/or more difficult/gimmicky levels)

SUPPORTS:
>>Shakespeare is a very good low rarity buster buffer with an on-demand targetable NP battery.
>>Caesar does not offer an NP charging skill but instead offers three targetable buffs that will stack multiplicatively with each other.
>>Ozymandias is both a good support and DPS option but his damage output is only good against casters and generally falls short when compared to berserkers when dealing with other classes.
>>Mash is the best kouhai any senpai can dream of. She can help keep your main DPS alive, has a good support deck QAABB that synergizes well with usually tripe Buster decked berserkers, and costs 0 to put in the party.
>>Waver (from Support); if you decide to run Caesar instead of Ozy, get this guy. A walking NP battery and buff machine.
>>Merlin (from Support); if you decide to run Ozy instead of Caesar, since Ozy has his own teamwide NP battery. The buster meme himself, need I say more? lol. Just look him up, he's just plain broken.

STALLER (Last Slot Usually):
>>Cu Chulainn. This guy just doesn't die. An excellent staller/clutch servant that will stay alive long enough to charge and pull off a last minute Gae Bolg when all hope seems lost. Best bro.

Thanks for reading if you did. Goodluck!

Suggesting to roll hans from friends point gacha, and keep leveling the level and skill hans and your mash 1st, since hans have a good skill. Good luck